Snakes Flashcards

Question

What are the three major clades of snakes? What unique anatomy defines them?

Answer 1

* Scolecopidia – Fossorial, blind snakes. * Vestigial eyes (rods only), blunt heads, short tails. * Multi-lobed liver, mandibular raking mechanism. * Oviparous, retain pelvic remnants. * Alethinophidia – Early blind snakes. * Most have well developed, bilateral ovaries, retain both pelvic vestiges and hindlimb remnents and left lung. * Caenophidia – Advanced snakes. * No hindlimb vestiges or left lung. * Many possess a well-developed tracheal lung.

Answer 2

* Proximal 1/3 – Esophagus, trachea, PT glands, thymus, thyroid, heart. * Second 1/3 – Lung(s), continuation of esophagus, liver, stomach, spleen, pancreas, GB, proximal SI, air sac. * Caudal 1/3 – Caudal small bowel, gonads, adrenal glands, kidneys, cecum, colon, cloaca.

Answer 3

* Vipers and many boas and pythons have facial pit organs. * True eyes, function via infrared and electromechanical radiation. * Trigeminal innervations differ by spp but innervations to the optic tectum of the brain allow for formation of images from sensory information.

Answer 4

Integument * No dermal osteoderms * Epidermal scales protect from abrasion and dehydration - enlarged head shields, small dorsal/lateral scales, wide ventral protective scales * Paired cloacal scent glands within base of tail in females and dorsal to hemipenes in males - defense and social signals; otherwise almost no skin glands * Shedding - ecdysis * Hormonal input from thyroid * Proliferation of epithelial cells from stratum germinativum forms new epithelial generation between stratum germinativum and the older outer epidermal layer * Younger epidermal layer keratinizes to resemble outer layer * Anaerobic glycolysis assists in separating the outer layer and acid phosphatase helps breaks down cementing material * Dull blue look as thin fluid forms between two layers - go blue for several days until fluid is resorbed and clears up * Should shed entire skin in one event with the spectacles * During shed cycle, many will refuse food and seek shelter in moist/humid site * Should resume eating immediately after ecdysis * Dysecdysis - r/o incorrect humidity, lack of proper substrate, improper handling, malnutrition, dermatopathy (trauma, ectoparasites) * Pigment cells within skin and microscopic surface structures for iridescence * Juveniles may have brightly colored tails to use as lures to attract prey * Captive propagation of color and pattern mutation morphs (albinos, leucistics, hypomelanistic, patternless, scaless) - problems with inbreeding

Answer 5

Cardiovascular * Position varies by species and ecological niche - arboreal snakes have more cranial hearts and aquatic snakes have more centrally located hearts * Heart somewhat mobile - possibly to help facilitate large prey passing through * Sinus venosus, right atrium, ventricle, left atrium * Communication between ventricles allows for shunting (R-L, L-R) * Paired aorta; left exits left side of ventricle and right aorta exits right side of ventricle -\> fuse caudal to heart to form abdominal aorta; left arch is larger than the right; pulmonary artery also exits ventricle * Paired carotid aa and jugular vv anterior to heart near trachea; jugulars can be accessed with cut down * Can control arterial pressure reflexively - control reduced when snake’s body temp is lower or higher than preferred * Oxygen dissociation curves may be influenced by temperature (not shown to be true in ball pythons) * Renal and hepatic portal circulations - recommended to administer renal eliminated drugs in front half to avoid nephrotoxicity and first pass effects (however studies indicate that clearance of drugs via renal-portal system may rely more on how kidneys clear a drug with tubular excretion affected more than glomerular filtration) * Ventral coelomic vein through coelom - Avoid in surgery by making approach at edge of rib cage between second and third dorsal (lateral) scale rows * Blood collections - ventral coccygeal vein and cardiocentesis most common * Jugular vein not common for venipuncture - ⅓ to ½ the distance between the base of the heart and base of the skull - collect blindly along medial rib margins or cannulated * Dorsal palatine vein - difficult without sedation; hematoma is problematic * Hematocrit 20-30% * Black rat snake blood volume is about 6% of body weight

Answer 6

Lymphoid tissue * Gastrointestinal tract (GALT) * Esophageal tonsils - boas, pythons, a few colubrids * May have significance in viral infections

Answer 7

Respiratory * Trachea has incomplete cartilaginous rings - ventral portion rigid; vascular lung can extend into trachea (tracheal lung) * Left lung is usually reduced or absent * Boas and pythons - left lung is moderately large * Right lung - near the heart -\> cranial to the right kidney * Cranial portion vascularized to function in gas exchange (vascular lung); caudal portion air sac (saccular lung) * Lungs - trabeculae with faveolar spaces * Cranial: thick, vascular, respiratory - typically where lesions are seen * Transitional: thin walled, semi vascular, variably respiratory * Caudal: membranous, avascular, saccular, nonrespiratory * Vascular lung - honeycombed units of gas exchange - faveoli * Inspiration occurs by muscular expansion of the rib cage creating negative pressure * Glottis is mobile and can extend cranial and/or lateral as necessary to facilitate breathing while ingesting large prey * Epiglottal cartilage enlarged/modified for defensive hissing - bull, gopher, pine snakes

Answer 8

Digestive * Prey moistened/lubricated with mucus from palatine, lingual, sublingual, and labial mucus secreting glands in oral cavity * Venom glands are modified labial glands in upper jaw below orbit * Teeth * 6 rows - one row on each mandibular bone and two on each maxillary region * not differentiated except for those with specialized fangs * replaced throughout life * generally modified pleurodont teeth with a socket attached to the side of the bone * vipers/pit vipers - fangs fold caudodorsally (solenoglyphous) * Elaphids (proteroglyphous) and fanged colubrids - fangs do not fold * Aglyphous - homodont maxillary teeth (more primative snakes) * Opisthoglyphous - rear fanged - enlarged teeth in posterior maxilla * Venom toxins: neurotoxins (neuromuscular junctions), hemorrhagins (destroy blood vessels), myotoxins (skeletal muscle); venom contains a variety of enzymes; including digestive * Tongue forked tip and lives within a sheath beneath the epiglottis - olfaction (vomernasal organs on roof of mouth); snakes that lose their tongues may stop feeding * Esophagus distensible, largely amuscular * Use axial musculature and skeleton to transport food * Lack cardiac (gastroesophageal) sphincter * Stomach muscular, distensible for digestion * Small intestine linear * Liver - left and right lobes, dorsal portal vein, ventral hepatic vein * Pancreas in triad with gallbladder and spleen distal to posterior tip of elongated liver; some sp have splenopancreas * colon empties into cloaca (cr-cd - coprodeum, urodeum, proctadeum); urates and feces temporarily stored in colon and cloaca; role in water conservation * Small cecum present in proximal colon - boas and pythons * Fat bodies within coelom - each side of cavity, small group cranial to heart * Shortest intestines of all reptiles.

Answer 9

Urinary * Paired lobulated elongated kidneys are caudal dorsally located last 25% of snout to vent length * Kidneys have craniocaudal orientation; right cranial to left * Ureters empty into urodeum - no urinary bladder * Males - distal convoluted renal tubules hypertrophy during repro season and contribute to seminal fluid production -\> kidneys have increased size and are paler * Uric acid is the primary nitrogenous waste -\> produce white to yellow urates * Unable to excrete urine at a higher concentration than plasma

Answer 10

Reproductive * Males - paired hemipenes invaginated in pouches in ventral tail base; during copulation a hemipenis evaginates into cloaca of female; can determine sex with lubricated probe * Gonads are cranial to the kidneys; right more cranial * Females - Ovaries near the pancreas; each oviduct has a separate opening into the urodeum * Some fossorial species have one ovary and oviduct * Fusiform testes between pancreatic triad and kidneys - enlarge and regress with season * Sperm carried in Wolffian ducts (vas deferens) into urodum and to the base of the hemipenes, travels up the sulcus spermaticus into females cloaca * Diverse reproductive behaviors * King cobras build nests for incubation * Egg brooding - pythons, some colubrids, some vipers * Some Crotalids exhibit parental care and remain with newborn until after shed * Snakes (species studied) have genetic sex determination * Females heterogametic: ZW, males homogametic ZZ in advanced snakes * Primitive snakes (boids, pythons) - males are XY and females XX * Sexual dimorphism is rare, females generally get to larger sizes * Most snakes reproduce sexually; some are parthenogenetic (blind snake, file snake); rare parthenogenesis reported in some other species

Answer 11

Musculoskeletal * Quadrate bones articulate with lower jaw and palatomaxillary arch to facilitate large prey ingestion * No mandibular symphysis; ribs not joined ventrally, body can expand * Pelvic vestiges and external spurs (used in courtship in boas and pythons) * Locomotion is relatively low energy * Lateral undulation - bend vertebral column laterally * Rectilinear locomotion - caterpillar crawling * Concertina locomotion - arboreal and fossorial snakes; energy expensive * Sidewinding - sand or mud; series of separate parallel straight lines * Caudal autonomy rare; no regeneration * No intervertebral discus

Answer 12

Nervous/Sensory * Unable to identify CN XI in snakes * No external auditory opening, tympanic membrane or middle ear - however shown to be electrophysiologically sensitive to airborne low frequency sound of 150-600 Hz * Eyes lack ciliary bodies - iris muscle movements move lens toward or away from retina * Lacrimal secretions flow through subspectacular space between cornea and spectacle and drain into oral cavity at the distal aspect of medial maxillae * Shape of pupil varies * Specialized infrared receptors - heat pits of pit vipers developed independently of labial pits in boas and pythons * Pit vipers - one organ on each side of head ventral to a line drawn between nostril and orbit; heat pits have a thin membrane stretched over an air filled cavity; heat info, direction and distance * Boas/pythons - labial or rostral scales or both, but varies with species * Innervation trigeminal nerve * Keepers feeding thawed prey may get bit if by hand - smell prey but sense heat of hand * Jacobson’s organs (vomeronasal) in roof of mouth - olfactory function, spherical, separate from the nose, innervated by olfactory nerve; lacrimal duct enters the duct of the vomeronasal organ; odors relayed to it by the forks in tongue * CNS diseases - Inclusion Body Disease (arenavirus) of boas and pythons (ataxia, opisthotonos)

Answer 13

Endocrine * Single or paired thyroid glands just cranial to the heart - controls growth and shed cycle * Thymus does not involute in adults, but difficult to find in adipose tissue cranial to the thyroid * Paired parathyroid glands often embedded in the thymus - calcium metabolism * Adrenal glands within the gonadal mesentery * Pituitary gland -appears to function similar to mammals * Pineal gland secretes melatonin * Clinical significance of endocrine function/dysfunction poorly understood in snakes

Answer 14

Behavior * Ectotherms - behaviorally regulate temperatures * Warmth seeking - ill, gravid, digesting prey * Facultative endothermy - brooding female pythons species able to maintain temps several degrees warmer than ambient temp * Thermal gradient recommended in human care * Brumation - winter dormancy Behavior * If cage is only opened for feeding, will likely exhibit a feeding response when cage is opened * Can train snake that prey item will be presented by tapping on enclosure with metal forceps * Feeding large snakes outside the cage may be recommended for safety * Courtship related interactions can be dramatic - pheromones, visual cues, tactile cues * Behavior can be completely different during mating season - aggressive; traumatic injuries can occur * Housing snakes singly usually referred - aggression, cannibalism (feed separately) * Wash hands prior to interacting with a snake, especially after handling prey or predator species * Having a king snake or other snake-eating snake nearby can affect behavior, likely due to pheromones

Answer 15

Housing * Snakes are escape artists - escape-proof cage; need latch or lock * Plastic shoe boxes, sweater boxes, modified aquaria, home made, commercially manufactured from fiberglass or ABS plastic - easy to clean and disinfect * Lighting requirements less understood compared to other reptiles * Attention to photoperiod - good health, successful reproduction * UVB not documented as necessary, but can allow for basking behavior/increased activity in diurnal snakes * Freshwater should always be available - water bowls cleaned and disinfected at least once weekly * Winter - forced air heat/drying effect -\> dysecdysis, respiratory disease * Too much humidity - harmful to desert species * Most snakes due well between 50 and 70% humidity with adequate ventilation * Plants, rocks, tree branches recommended as enrichment * Substrate - newspaper or paper for hospitalized patients unless fossorial or aquatic * Hide box/shelter area recommended * Large enough to allow for activity * Cage styles * Basic - one substrate, water bowl, hide box, plant/tree branch * Wet to dry - one or two substrate, moist area and dry area * Tree-layer -bottom is gravel (can be moistened), middle sand, top is mulch * Desert - thick sand substrate, small water bowl, good ventilation * Swamp tea - rare; dilute solution of tea for water environment * Natural setups and outdoor enclosures - outdoor must be escape, vermin and vandal proof * Venomous snakes should be housed in enclosures equipped with a locking mechanism and the snake must be visible from the outside. Appropriate signs and emergency bite protocol.

Answer 16

Thermoregulation * Ectotherms need thermal gradient * Heat tapes and thermostats may be used * Light bulbs and heat rocks are inefficient and can be dangerous * Temperature mosaic (top to bottom, front to back). * External infrared heat sources that create basking zones. * Humidity – Too low predisposes to chronic dehydration, dysecdysis, chronic renal problems. * Excessive associated with development of dermatitis. * Humidity chambers can be created. * UV light generally not considered critical. * Recent study showed certain snakes increase circulating 25 hydroxyvitamin D3 concentrations when exposed to UVB radiation.

Answer 17

Feeding and nutrition * All snakes carnivorous, but diet varies by species * Some specialized diets. * Commercial sources recommended to reduce parasite transmission. * Incorrect prey is common cause of anorexia * Whole rodents are nutritionally complete, but rodents should be fed nutritionally complete rodent diet * Frozen thawed preferred - avoid bite wounds/injuries of live prey, humane considerations * Freezing few days before feeding will also help reduce parasite transmission. * Live items may cause extensive trauma to snakes if left alone in the enclosure. * Avoid feeding by hand - radiates heat, avoid bites * May also be anorexic if appropriate environmental temperature is not provided hat * Normal not to feed during ecdysis * Feeding frequency varies by species, age, and season; juvenile and adults - once weekly feedings; babies need 2 feedings a week * Juveniles may be fed more often (every 5-10 days). * Adults every 1-2 weeks. * May also be fasted periodically for 4-8 weeks without harm. * When cycling a female, more frequent feedings are often done to increase weight prior to the fasting period associated with the gravid state. * Male snakes will often refuse food during breeding season for weeks to months. * Snake spp that consume fishes and amphibs will generally eat more often and two to three times a week may be appropriate. * Many snakes may not feed during gestation and breeding males may have reduced appetite

Answer 18

Brumation * Temperate zone snakes (colubrids) must be brumated to induce successful reproduction * Fed well during summer and fall, then feeding is stopped and snakes can pass stool to empty gi tract before cooling cycle * Cage temperature slowly dropped over several weeks - 2.8 deg C every few days for a total drop of 10-14 deg C conditions the snakes to enter brumation * Maintained in dark with water, but no food for 3 months * Then slowly increased temperatures and feed 2-3 weeks later * Most tropical boas and pythons do NOT require drastic temperature drop (5 deg C) suffices and may only need to occur at night; total darkness not required; tropical snakes prone to respiratory or neurologic disease if too cool * Neonate temperate zone snakes that are not yet feeding if in good condition can be brumated to induce them to feed after brumation * No snake should be brumated if not in good physical condition or showing evidence of illness

Answer 19

Quarantine (F8): * Progression of infectious dz in snakes may be significantly slower. * Quarantine periods of at least 90 days are recommended. * Testing should be targeted toward agents causing chronic dz that may take longer than a quarantine period to manifest, especially those that are environmentally stable with direct LC. * Greater collection threats. * Some of the snake pathogens that merit most significant consideration for quarantine pathogen – Adenoviruses, arenaviruses, Chlamydophila pneumoniae, Cryptosporidium spp.

Answer 20

Restraint - (Ch 20 Mader, F8) * Gentle manual restraint by grasping head immediately behind the mandible. One handler for each 3-4 ft of snake. * Venomous snakes should only be handled by trained individuals with appropriate equipment (tongs, hooks, tubes, shift boxes). * Aggressive or unknown disposition - identify and control head; chapter recommends placing thumb and middle finger laterally behind the jaw and index finger on top of the head * Additional handler recommended for large boids or pythons, even if docile - safety and to support lengthy body * Physical Restraint (West): * Never handle lizard spp with tail autonomy by the tail. * Nonvenomous snakes restrained by grasping the neck caudal to the head while supporting the body with the other hand.

Answer 21

Anesthesia and Analgesia (F8) * Dissociative anesthetics, propofol, local anesthetics, inhalants most commonly used. * Venomous – Restraint in tube then propofol or chamber/tube induction with gas. * Isoflurane most common. * Nitrous oxide has been used as a supplemental agent during induction in monitor lizards to reduce MAC. * Primary benefit of inhalant anesthetics over injectable agents is more direct control over the anesthetic during the procedure. * Most snakes will become apneic at surgical plane of anesthesia, need ventilation 6 BPM. * Recovery should be on room air. * Propofol – IV, IO, IC; rapid induction and recovery times, ventilation needed. * With IC injection, study showed lesions in cardiac tissues were mild and resolved after 14 days. * Alfaxalone – Heavy sedation in one study at 9 mg/kg IV, easily intubated, may be preferable to propofol. * Less cardiorespiratory depression, shorter induction times, shorter total ax duration. * Telazol – Low doses have been used for large, aggressive snakes before handling or intubation. * Snakes show antinociceptive effects in response to butorphanol but not morphine, unlike other reptile groups. Effective dose of butorphanol is much higher than other spp (20 mg/kg).

Answer 22

Ch 97 Snake Celiotomy - Mader * Avoid incising snake skin near shed cycle - skin softer and more difficult to handle * Fasting - recommended to minimize diameter of gastrointestinal tract * Incision made laterally between first two or second and third rows of dorsal scales * Avoid incising scales if possible * Avoid midline ventral abdominal vein * Incision may need to be long due to anatomy * Coelomic membranes are thin and tend to be relatively transparent * Consider stay sutures to find again at closer * Doesn’t hold sutures well * Simple continuous suture of absorbable monofilament material recommended * Body wall closed with a simple continuous monofilament absorbable suture * Skin closed using everting pattern with horizontal mattress sutures of a nonabsorbable monofilament suture * Everting pattern - recommended due to keratinized skin’s tendency to invert à reduced contact of cut surfaces à poor healing * Orient knots dorsally to help minimize adhesion of substrate debris to knots * No or limited access to submersion of incision in water recommended for 14 days post-op * Tissue glue around incision site - may reduce contamination during healing process in aquatic species * Suture removal – typically 6 weeks post-op * Surgery may hasten shed cycle, may shed sutures earlier * Changes in husbandry, such as use of a paper substrate to increase cleanliness, postop fasting, reduction in prey size to reduce the incidence of dehiscence, and increases in temperature within POTZ to accelerate healing recommended

Answer 23

Surgery (F8): * Presurgical workup should include PE, CBC, chem. * Supplemental heat should always be provided. * Coeliotomy most common surgical procedure. * Large abdominal vein runs along ventral midline. * Approach should be between the second and third rows of lateral scales. * Closure in two layers – body wall and skin. Skin is holding layer. * Everting suture pattern for skin. * One study showed polyglyconate and poliglecaprone were the least reactive materials. * Remove sutures 4-8 wks after surgery. * GI surgery – FB, management of intestinal prolapse or intussusception, excision of masses or granulomas, relief of impaction. * Serosa-to-serosa contact for closure of GI incisions. * Two layer closure ideal but may not be possible in small snakes. Can use a serosal patch. * Coelomic cavity should be irrigated with warm, sterile saline after GI closure. * Dystocia – Generally follicular. * Salpingotomy indicated in reproductively valuable animals, where noninvasive techniques have failed, or if rads show natural passage not possible. * Incision should be in avascular region of the oviduct. May need more than one incision to access all eggs or fetuses. * Subspectacular abscesses – Often from ascending infections within oral cavity. * Excision of spectacle to gain direct access. * Small triangular wedge, allow for drainage. * Topical antibiotic three to four times daily to manage infection. * Spectacle will regenerate but the original incision must remain open until infection is under control.

Answer 24

* Gout * Kidneys swollen- multifocal to miliary white/tan pinpoint nodules * Impression smears can differentiate urate stasis (sexual segment streaking in males) from true renal gout * Radiating urate tophi will be present in gout (vs round or amorphous urates with urate stasis) * Histo: tophi appear as empty spaces and are surrounded by epithelioid macrophages, multinucelated giant cells and heterophils * Secondary gout associated with dehydration is most common in snakes * Uric acid deposition in kidneys usually precedes other tissues (pericardial sac, pleura, serosa of liver, etc) * Articular (intervertebral) gout is not as common, but can occur

Answer 25

* Chronic vertebral osteopathy * Proliferative, degenerative, inflammatory lesions in vertebral bodies, intervertebral joints, and ribs * Bony remodeling, new bone and fibrocartilage formation, sclerosis, vertebral and costal spondylosis and ankylosis, degeneration of the articular cartilage, osteomyelitis, osteoarthritis, osteonecrosis, pathologic fractures * Irregular patches of woven and lamellar bone with mosaic reversal lines * Etiologies: trauma, viral, nutritional (hypervitaminosis A and D), chronic inactivity (confinement), chronic or resolved bacterial infections * *Salmonella* (*S. enterica arizonae* associated with osteotropism in colony of ridgenose rattlesnakes), *Pseudomonas, Staphylococcus*

Answer 26

* Nutritional diseases * Both temp extremes will lead to anorexia and regurgitation if food is taken. * Obesity is the most common nutritional disorder observed in captive snakes (F8). * Reducing wt of obese snake should be done slowly over 6-12 months. * Rapid reduction of food may lead to hepatic lipidosis. * Captive snakes should not be fed wild-caught food items. * Rodent suppliers who use pesticides to manage ectoparasites in their operation should be asked to stop use of pesticides a min of 3 wks before shipment. * Avoid NSHP by dusting with calcium or vitamin sources for snakes fed neonatal rodents. * Piscivorous snakes vet strictly fish may be predisposed to thiamine and vit E deficiencies. * Neuro signs, loss of righting reflex, abnormal locomotion, muscle tremors, blindness. * Vit E deficiencies leading to steatitis may occur when snakes are fed fish high in PUFAs. * Feeding variety of fish spp and not a high percentage of fatt, cold water fish, is an effective prevention strategy. * Egg eating - biotin deficiency caused by uncooked avidin binding it

Answer 27

* Neoplastic - more often diagnosed with neoplasia than other reptile species * Lymphoma - usually multicentric, though esophageal MALT reported * Lymphocytes most commonly large and blast-like * CD3+ T-cell lymphomas seem to be most common (biased as B-cell markers have limited diagnostic utility) * Other hematopoietic: leukemia, mast cell tumors, histiocytic origin round cell tumors * Squamous cell carcinoma * solitary or multifocal; common in oral cavity * Invasive, locally destructive, metastasis uncommon * Association with chronic inflammation (stomatitis) has not been fully examined * Other oral cavity tumors: fibrosarcoma, amelanotic melanophoroma, oral tumors of odontogenic origin, ameloblastoma * Gastric, intestinal, cloacal adenocarcinomas * Gastric: locally invasive and expansile masses - tubulopapillary arrangements of columnar to cuboidal neoplastic epithelial cells with scirrhous response * Intestinal are common in colubrids, distal si and colon common sites * Signet ring or mucinous cell morphology * Pancreatic and pancreatic duct adenocarcinomas - well differentiated, but can be aggressive and metastasize * Exocrine pancreas adenomas and nodular exocrine hyperplasia are a common incidental finding * Renal adenocarcinomas * large, solitary tumors composed of tubules lined with epithelial cells and scirrhous stroma that expand and disrupt normal parenchyma * Urate tophi often present within neoplastic tubules and desmoplastic stroma * Large cystic cavities with urine and urates can be seen * Renal tubular adenomas - inicental finding - solid nodular foci of tubular proliferations that may compress adjacent tissue but lack desmoplastic response * Reproductive - varial metastases * Ovarian carcinoma, sarcoma and benign granulosa cell tumors * Oviductal adenocarcinomas - exophytic, papulary, composed of cords of neoplastic cells that may have areas of hemorrhage, necrosis, and inflammation * Integument: * Squamous cell carcinomas most common with cloacal region (hemipenes, cloacal glands, cloacal skin) * Chromatophoromas * melanophoromas most common (gray or black composed of neoplastic spindled cells with prominent black cytoplasmic granules); variable activity (some invasive with intravascular and visceral mets) * Iridophoromas: grossly white to light gray dermal masses of spindle cells with golden brown to yellow/green cytoplasmic pigment (most often benign) * Xanthophoromas * Cutaneous soft tissue sarcomas - locally invasive, interlacing bundles and streams of neoplastic spindle cells (fibrosarcomas) most common * Many other benign and malignant neoplasms (smooth muscle, endothelial, mesenchymal, hepatic, biliary (often cystic), thyroid and parathyroid adenomas, pheochromocytomas, interrenal (adrenocortical) adenocarcinomas, intratracheal chondromas (airway obstruction in ball pythons), hemangiosarcomas of heart and spleen, etc

Answer 28

* Herpesvirus infections uncommon - cobras, kraits * Cobras: inflammation, degeneration, necrosis of venom gland epithelium associated with decreased venom production or poor quality venom, hepatic necrosis. * Suggestive of herpesvirus: Hepatocellular necrosis with amphophilic intranuclear hepatocellular inclusions in clutch of boa constrictors concurrent with pancreatic, renal, and adrenal intranuclear inclusions * All herpesviruses in reptiles and birds are in the subfamily Alphaherpesvirinae. * Known for latency, should be considered infected for life.

Answer 29

* Ranavirus (iridovirus) * Novel ranavirus isolated in green tree pythons with systemic disease * Ulcerative and necrotizing rhinitis, stomatitis, pharyngitis, hepatic and splenic necrosis * Erythrocytic iridovirus * Erythrocyte inclusions in free-ranging northern water, plains garter, eastern ribbon snakes * Healthy and anemic snakes can have inclusions * The iridoviruses are environmentally stable. * Temp dependent disease manifestation for iridoviral dz – The best therapeutic strategy is to provide temp options for the snake outside of temps at which disease manifests (F8).

Answer 30

* Adenoviruses * Sporadic gastrointestinal disease * Boa constrictors - hepatocellular necrosis with large basophilic intranuclear hepatocellular inclusions * All adenoviruses of squamates that have been analyzed to date cluster in genus Atadenovirus. * Hepatitis, enteritis, gastritis, esophagitis, splenitis, encephalopathy. * Snake adenovirus 1 – Boids, colubrids. * Snake adenovirus 2 – Viperids and colubrids. * Snake adenovirus 3 – Colubrids.

Answer 31

* Inclusion body disease (IBD) – Arenaviridae. * Global, transmissible, progressively fatal * Captive boas and pythons * Arenavirus implicated as cause * Central nervous system abnormalities- flaccid paralysis, stargazing, torticollis, chronic regurgitation, loss of body condition * Some individuals succumb in weeks while others survive for months - challenge in captive collections * Variably sized, eosinophilic to amphophilic, intracytoplasmic inclusions * With more rapid progression (particularly pythons), inclusions typically in CNS) * With more chronic disease (boa constrictors), inclusions throughout body, lymph and blood * Disease progression may take months or years. * Secondary infections common, immunosuppression Mader 2019 – Ch. 154 Inclusion Body Disease * Definition * Arenavius = enveloped RNA virus * Inclusion body disease → chronic, multisystemic wasting disease * Primarily affects boids but also colubrids and vipers * Snake mite may be vector * Clinical Signs * Regurgitation (common in boas not pythons), incoordination, disorientation, opisthotonus, torticollis, lack of righting reflex * Secondary: pneumonia, stomatitis, lymphoproliferative/neoplastic dz * Ball pythons often die within weeks * Boas die after months to years * Acute disease → Leukocytosis, lymphocytosis, lower total protein and globulin, elevated AST * Gross Lesions: * Splenic and pancreatic atrophy * Intracytoplasmic eosinophilic to amphophilic inclusions * In multiple tissues in boas * In CNS in pythons * Diagnosis * RT PCR * IHC * Inclusions on blood smear * Histo * Virus isolation * Prognosis and Prevention * No treatment; euthanasia recommended * Poor prognosis * Quarantine for \> 6 months, repeat testing

Answer 32

* Nidoviruses * Fatal respiratory disease in ball pythons and an Indian python reported * Open mouth, labored, audible breathing; copious mucoid to exudative oral/glottal/tracheal discharge * Catarrhal and necroexudative stomatitis, tracheitis and pneumonia present - expanded faveoli, mucus present in gi tract * Epithelial hyperplasia and necrosis with lymphoplasmacytic and heterophilic inflammation seen in oral cavity, nasal cavity, trachea, esophagus, lungs * Profound pneumocyte hyperplasia

Answer 33

* Paramyxoviruses (ZPP) - primarily viperids and crotalids, others susceptible * Respiratory disease in captive snake (OPMV) * Lungs - thickened, edematous; hemorrhage and necroexudative material in airways throughout lung (hemorrhage can also occur in oral/nasal cavities, glottis, esophagus and coelomic cavity * Similar histologic changes to other viral pneumonia - pneumocyte hyperplasia and inflammation * Presence of both pulmonary epithelial syncytia and eosinophilic intracytoplasmic inclusion bodies within pneumocytes are diagnostic features along with the absence of segmental esophagitis can help differentiate * Pancreatic inflammation and necrosis may be present * Concurrent neurologic disease (meningoencephalitis, lymphocytic perivascular cuffing, demyelination, axonal and neuronal degeneration, intracytoplasmic gleal and intranuclear neuronal viral inclusion bodies * Neurologic, respiratory, and acute immunosuppressive diseases in snakes. * Two clades: Ferlaviruses and Sunshine Virus. * Temperature dependent. * PCR with sequencing recommended for most clinical applications (F8). Mader 2019 – Ch. 158 Paramyxoviruses (Ferlaviruses) * All partially characterized reptile paramyxoviruses (ssRNA) are within genus Ferlavirus, family paramyxoviridae. * Except: Sunshine virus – Australian pythons. * Documented mainly in snakes, also lizards and chelonians. * Clinical presentation: * Variable – No CS to severe resp dz with or without tracheal exudate. * Neurologic signs. * Gross lesions: * Range from none to caseous-necrotic material in lungs, hemorrhages, and dermatitis. * Microscopic lesion: * Proliferative interstitial pneumonia with occasional intracycoplasmic eosinophilic inclusions is characteristic of Ferlaviruses infection * Sunshine virus – severe spongiosis of white matter of hindbrain. * Chelonian paramyxovirus infection – pneumonia, degenerative liver dz, stomatitis, dermatitis. * Transmission: * Intratracheal administration leads to disease. * Vertical transmission also considered for Sunshine vvirus. * Dx confirmation: * Serology, molecular tests, VI, IHC, histo, EM. * Most common serologic test – Hemagglutination inhibition. * Most common molecular test – RT-PCR, targets L gene. * Specific PCR available for Sunshine virus. * Can detect Ferlavirus RNA in tissues as early as 4 days post infection, animals remain positive at least 49 days. * Lung, SI, pancreas, brain tissues of choice for post mortem dx. * Antemortem – Combine RT-PCR and viral isolation on tracheal wash, viral detection as early as 16 days post infection. Cloacal swabs may be positive as early as 28 days post infection. * HI titers require minimum of 16 days, becomes more robust at 28 days. * Ideal dx – molecular, serologic, histopathologic investigations and VI. * TX – None; Supportive care. * Px and prevention: * Quarantine up to 6 mos while carrying out repeated molecular and serologic tests. * Isolation and testing of reptiles with clinical signs. * Prognosis is guarded to poor.

Answer 34

* Bacterial stomatitis * Common and often associated with poor husbandry, concurrent disease, or dysecdysis * Ulcerative and heterophilic inflammation of oral mucosa, especially at junction between labial scales in early disease -\> exudation and necrotic debris accumulation progresses to large areas of oral and pharyngeal mucosa and extend to choana * Heterophilic exudate accumulation within lingual sheath chronically -\> necrotizing glossitis * Can extend to cause osteomyelitis and bone loss * Septicemia and bronchopneumonia common

Answer 35

* *Salmonella* * Normal gastrointestinal flora and common pathogen * *Salmonella enterica* subspecies e*nterica* (I), *arizonae* (IIIa) and *diarizonae* (IIIb) * Septicemia, heterophilic dermatitis, necrotizing inflammation of GI, osteomyelitis

Answer 36

* *Mycobacteria* * Local or disseminated * Pulmonary myobateriosis common - boids overrepresented * Typical reptilian granulomatous inflammation with central cores of necrotic debris surrounded by epithelioid macrophages, multinucleated giant cells and heterophils, with an outer rim of lymphocytes and plasma cells (identified with acid fast stains)

Answer 37

* *Chlamydophila pneumonia* * Obligate intracellular bacterium * granulomatous disease in puff adders and emerald tree boas * Small basophilic inclusions

Answer 38

**Etiology:** *Ophidiomyces ophidiicola* * Also referred to snake disfiguration syndrome (but not the case in all snakes) and snake fungal disease (SFD), but should actually be referred to as Ophidiomycosis * Fungus w/ relatively slow growth * Resistant in environment bc produce enzymes that degrade all kinds of substrates allowing survival without a host * Maximal growth at 25˚C, but can still grow at as low as 14˚ * Growth impeded at 35˚C * Resistant to pH of 5-11 (optimal is 9) **Distribution and host range:** * Captive snakes in NA, Europe and Australia * Likely present as early as the 1980s but has been frequently misdiagnosed * Also detected in wild snakes in NA and recently Europe * Strictly limited to snakes including crotalids\*\*, colubrids, acrochorids, boids, elapids * \*\*Likely that all snakes are susceptible **Epidemiology:** * Rarely recovered from healthy animals (only 1 isolate from a snake with no lesions) = strong association btw presence of fungus and presence of lesions/disease * Often involves recently capture animals, suggesting that they were carriers and stress of captivity resulted in disease * Discovered in captive snakes before in the wild * Spillover less likely, disease was probably present for a long time but increased expression and severity due to climate change and other factors * Severity of lesions varies between species: * Usually most severe in massasaugas and less in pine snakes * Individual variation within species also possible * \*\*Contagious between snakes **Pathogenesis:** * Hyphae release keratinases and proteases 🡪 epidermal necrosis, can extend to underlying muscles and bones (esp. in massasaugas)

Answer 39

**Clinical presentation:** * CS: focal or moultifocal and coalescing scale necrosis, esp. on head and face, discolored scutes and scales with epidermal brown crusting, sometimes hyperkeratosis * Very rarely dissemination and fungicemia * Swelling causes by granulomas in subcutis * More frequent ecdysis * Lesions can impede hunting and feeding and cause behavioral changes like seeking open areas and exiting hibernacula during winter * In rat snakes (and other colubrids); swelling along body caused by subcutaneous mycetomas * If mild lesions, can improve with shedding during summer months (increase in T˚ leads to more efficient immune response), but if lesions begin at ingress (beginning of winter), dropping T˚ favor fungal growth in increasingly torpid animals --\> worse prognosis although some survive **Lesions** * Histo: necroulcerative, heterophilic, ulcerative dermatitis; overlying serocellular crusts with necrotic debris and proteinaceous material, parallel walled branching septate hyphae; along surface of crusts - cylindrical fission arthroconidia may be present (similar to CANV) * Mild dermatitis may resolve, severe cases -\> facial distortion, deep chronic granulomatous heterophilic inflammation associated with severe osteolysis and osteomyelitis * Disseminated infections with widespread visceral granulomas

Answer 40

**Dx:** * Most common fungal disease in captive and wild snakes and should be ddx for any snake with cutaneous lesions * Cytology: presence of arthroconidia very suggestive * Culture: growth on selective agars that contain cycloheximide (inhibits ubiquitous saprophyte fungus that would otherwise overgrow the medium) * PCR **Tx:** * Some may improve on their own if mild lesions at beginning of exgress (end of hibernation) * Supportive measures (fluid, thermal, nutritional) with topical and systemic antifungals (Itraconazole, voriconazole, terbinafine) * Problematic in venomous snakes, osmotic pumps and implants being investigated * Duration of tx should extend beyond resolution of skin lesions * Surgical debridement when no improvement following shedding * Snakes with lesions should not be allowed to hibernate * Strict isolation and disinfection (bleach, ethanol, quaternary ammonium)

Answer 41

* Fungal dermatitides - histologically similar to SFD, but caused by other fungi (also order Onygenales) * *Paranannizoposis (P. californiensis, P. crustacea*) - tentacled snakes * *P. australasiensis* in aquatic file snakes * Common with tentacled snakes with poor water quality * Touch prep cytology of ulcerated or necrotic lesions may yield characteristic rectangular arthroconidia suggestive of Onygenales. Culture best at 25C.

Answer 42

* ***Rhabdias* and *Strongyloides*** larvae both initially target pulmonary tissues -\> pneumonia in severe infections. *Rhabdias* remains in the lung while *Strongyloides* mature in intestines -\> proliferative enteritis with severe infections

Answer 43

***Serpentirhabdias dubielzigi*** - ocular disease in captive ball pythons: opaque spectacles, swelling of oral/facial/periocular tissues; subspectacular space expanded by inflammatory and proteinaceous debris as well as parasites of all life stages

Answer 44

* Ascarids often associated with gastric lesions * Mature *Ophidascaris* embed in caudal esophageal and gastric wall; visceral larval migration * *Kalicephalus* (snake hookworm) - gastritis, ulcerative enteritis, hemorrhage, impaction

Answer 45

* Cryptosporidiosis - *Cryptosporidium serpentis* * Enlarged and firm stomach - may cause bulging of body wall * Gastric mucosa thickened with prominent rugae and mucus accumulation * Gastric mucosa hyperplastic with more connective tissue in the lamina propria and submucosa; gastric glands dilated, atrophy of granular and serous cells, hyperplasia of mucus cells, intracellular extracytoplasmic cryptosporidial oocysts attached to microvillar surface * *C. saurophilum* (*C.varanii* new name) primarily in lizards can also be found in snakes - chronic enteritis, crypto is at apical margin of enterocytes * Monogenous – Entire LC in one host. Transmission is fecal-oral. Also fomites. * Thick-walled sporozoite resistant to desiccation and most disinfectants. * Only ammonia 5% and formal saline are effective against oocysts. * Direct LC. * C. serpentis has gastric tropism. * Poor growth, wt loss, regurgitation, gastric hypertrophy and midbody swelling. * C. varanii usually present with wasting, diarrhea without regurgitation. * Intestinal disease. * Gallbladder and intra and extrahepatic bile ducts contain organisms. * Antimortem dx by demonstrating oocysts in mucus-coated regurgitated food, gastric lavage, impression smears of biopsy samples, or in feces by using AF stains. PCR with speciation. * During quarantine, AF screening of fecal samples with PCR for any positive results should be considered. * Endoscopic bx or laparotomy samples may be evaluated for the presence of the organism. * Tx not rewarding, not effective. * Culling confirmed cases from collection and prevention are best control methods.

Answer 46

* Eimeria spp (direct LC), isospora spp (direct LC), caryospora (direct or indirect LC). * Young animals heaviest infestations. * Necrotizing cholecystitis, fibrosis, epithelial ulcerations, catarrhal and diptheroid inflammation of SI. * Evaluation of fecal material for dx, or PCR. * PCR with sequence is important, since mouse spp that may bd ID on fecal may not be morphologically distinguishable from pathogenic coccidian spp.

Answer 47

* *Entamoeba invadens* * Necrotizing hepatitis and enterocolitis, hemorrhagic. * Common in mixed reptile collections (reservoirs are herbivorous lizards and turtles) * Direct lifecycle, transmission is fecal-oral. * Ingested cysts -\> invasive trophozoites in gi tract -\> segmental to diffuse mucosal necrosis of primarily large intestine -\> access to portal circulation and liver -\> necrotizing hepatitis from trophozoites as will as alimentary bacteria * Tx of choice is metronidazole for trophozoites with or without paromomycin for cysts. * Colubrids and rattlesnakes may be more sensitive to metronidazole, and these spp should be tested at the lower dose and frequency. Temp may play a significant role in therapy (F8).

Answer 48

* Digenetic trematodes rarely assoc with disease. * Indirect LC with gastropod. Self-limiting without gastropod host. * Pseudophyllidea – Genera Bothridium and Bothriocephalus are mainly parasites of boids. * Have been associated with severe edema and hemorrhage in SI and mild chronic enteritis. * Genus spirometra widely distributed among snake genera. * Snakes are IM or paratenic host. * Plerocercoid life stage commonly seen in snakes. * Subcutaneous, soft swelling sof the body aka spargana. * Edema and hemorrhage. * Tx by surgical incision and extraction. * Adults found in the SI. * Pseudophyllidean eggs are operculated and float in salt solutions. * Renifers aka lung flukes may be encountered in the oral cavity. * Adults migrate from mouth into lungs, attach to epithleial lining and cause focal erosions. * Secondary bacterial pneumonia. * Stylodora infects urinary system, collecting tubules and ureters. * Renal tubular dilatation with chronic interstitial nephritis. * Tx with prazi.

Answer 49

* Pentastomids. * Obligate parasites of lower respiratory tract of vertebrates. * All require IM host for LC, zoonotic potential for some spp to humans. * Armilifer and Porocephalus. * Dx with eggs in lung washes or feces, survey rads. * Larvae possess hooklets. * Tx in larger snakes with endoscopic removal. Some chemotherapeutic agents have been suggested. * Fenbendazole may cause significant bone marrow suppression and damage to gut epithelium in many snake spp.

Answer 50

* Ectoparasites - mites frequently associated with dysecdysis * *Ophionyssus natricis* - can lead to anemia and debilitation; possible role in disease transmission. Both larval and adult forms of the mite are parasitic. May be involved in Aeromonas hydrophila transmission/possibly IBD. * Lung mites incidental - *Entonyssus* and *Hamertonia* * Bathing snake in water or applying mineral oil topically, topical and parenteral ivermectin, OP, topical permethrin, and topical pyrethrins tx for mites. * Tx snake and environment. * Provent-a-Mite has been found to be both effective and safe when directions on label are followed.

Answer 51

* Venipuncture: Heart, jugular veins, ventral coccygeal vein. * Cardiocentesis most reliable in snakes \> 200 g. * Jugular veins located cranial to heart where lateral and ventral scales meet. * Cranial to heart on medial aspect of ribs. * Ventral coccygeal vein on ventral midline, using gravity may be useful, avoid hemipenes.

Answer 52

* Hematology: * Blood counts and chemistry values are affected by environmental conditions, reproductive status, season, locomotion, and nutrition. * Blood volumes in reptiles vary from 5-8% of total weight, up to 10% of that amount can be collected safely. * EDTA or lithium heparin. * Mixing blood samples with 22% albumin (1 drop alb to 5 drops blood) recently shown to reduce WBC damage during smear process.

Answer 53

BEHAVIOR * Increase in activity - high environmental temperature, insufficient hiding spots, mate seeking, nest seeking, hunger, thirst, ectoparasites, improper substrate, odors, lighting * Defensive - new captive, startled * Lethargy - ill, gravid, digesting, cold, near shed, preparing for brumation * Snake always in water bowl - too dry, too warm, near ecdysis, mites

Answer 54

CARDIOVASCULAR * Anemia - blood loss, neoplasia, lymph dilution, parasites possible but rarely cause symptoms * Oral petechiation (rare) - stomatitis, septicemia, diffuse intravascular coagulopathy, hyperthermia, intoxication, rarely with anemia * Avascular necrosis (tail tip) - parasitism (*Alaria* flukes, microfilariae), trauma, thromboembolic disease (female Burmese pythons) * Bradycardia/weak heartbeat (hypovolemic shock, anemia, dehydration) vs normal slow (inactive snakes, cooler environment) * Burmese python with endocarditis - *Salmonella, Arizona*, and *Corynebacterium* sp * Myocarditis - Chlamydiosis in snakes * Cardiomegaly - cardiomyopathy (reported in mole king and Deckert’s rat snake), pericardial effusion, congenital (incomplete atrioventricular valve in neonatal boa constrictor), mass * Mitotic figures in peripheral blood - normal finding, unusually high suspicious of lymphosarcoma

Answer 55

GASTROINTESTINAL * Emesis (vomiting and regurgitation difficult to distinguish) - food too large, to many food items, suboptimal temperatures, postprandial handling, stress, intraspecific interactions, obstruction, functional stasis, gastritis/sepsis, parasitism (*Cryptosporidium*), stomatitis, intramural or extramural masses (neoplasia, granulomas, abscesses), toxins * Chronic regurgitation - associated with Chlamydophila in population of emerald tree boas * Concurrent respiratory disease can be present with any GI sign * Diarrhea - normal (rodent fed king or rat snakes may have soft stools after a meal of day-old chicks), low temperatures, parasites, foreign bodies, too large meals, inappropriate diet, infections (bacterial, fungal, viral) * Gingivitis - mass, broken jaw, stomatitis * Inactive tongue - tongue sheath abscess or injury, trauma, necrosis * Oral petechiation - sepsis, stomatitis, hyperthermia, intoxication, possibly DIC * Oral edema - bacterial cellulitis, uremia (renal failure), head/intermandibular cellulitis (bacterial), trauma associate with getting stuck in a hole * Oral discharge/mucus - stomatitis, esophagitis, gastritis, tracheitis, pneumonia * Dental disease (loose teeth) - stomatitis, osteomyelitis * Stomatitis - aerobic or anaerobic bacterial infections; husbandry often predisposing factor * Enlarged tonsils - boas/pythons with inclusion body disease (arenavirus) * Mass in precardiac region - esophagus, respiratory, ribs * Coelomic mass/midbody swelling- intestinal granuloma, abscess, neoplasia, foreign body, meal, constipation, cryptosporidiosis, extraintestinal (reproductive) * Constipation - meals too large, too frequent, too furred, low temperatures, mass effects, poorly absorbed or infected fetal yolk mass (neonates) * Prolapse - cloacal, oviductal, hemipenal, colonic

Answer 56

OCULAR * Retained spectacles - dysecdysis, periorbital mites, trauma, ocular abscessation, husbandry (lack of cage furniture, humidity, temperature), normal (if removed leads to exposure keratitis) * Swelling, cloudiness, dermatitis - *Ophidiomyces ophidiicola* * Exophthalmia - intraocular mass, abscess, granuloma; retrobulbar mass, subspectacular abscessation, increased subspectacular fluid (blockage of lacrimal duct), may be associated with stomatitis or respiratory infection * Microphthalmia - infected eye becoming phthisical, congenital aplasia, reduced palpebral fissure * Anophthalmia - congenital, normal (blind, thread snakes) * Cloudy eyes - normal, retained spectacle, subspectacular abscess, inflammation of subspectacular space or cornea, panophthalmitis, penetrating wound, temporary post brumation vitreous haziness * Cataracts- geriatrics, sequela of low brumation temperatures, other * Blindness - cataracts, uveitis, hyphema, retained spectacles

Answer 57

DERMATOLOGICAL * Abscesses - bacterial (usually), fungal, mixed; causes include husbandry, parasites, trauma/burns, rib fractures, spinal osteomyelitis * Masses - abscesses until proven otherwise, granulomas, neoplasms (chromatophoromas appear to be more common in diurnal sp), acariasis (myiasis is rare), sparganosis, generalized cellulitis * Caudal masses - impacted/abscessed glands/hemipenes, constipation, urates/feces, fecaliths, uroliths * Lipomas - older females (especially corn snakes) * Snout rubbing/abrasions - inadequate hides, hormonal (males), rough cage edge or screen top * Skin lesions/dermatitis - chemical or thermal burns (blister disease vesicles, petechiation), poor cage hygiene, trauma (damage, bruising, rodent), bacterial, fungal (dermal granulomas and crusting dermatitis of *Ophidiomyces ophiodiicola*), viral, ectoparasites (*Ophionyssus* mites, ticks) acanthocephalans (small ulcerated wounds at exit), * Wrinkling - lethargy/malnourished, dehydration, acariasis, dysecdysis, postpartum females * Skin rupture syndrome (separation of epidermal-dermal layers - cachexia, hypovitaminosis C * Dysecdysis - ectoparasites, malnutrition, dehydration, improper humidity, improper substrate, systemic disease, debilitation, rough handling * Increased shed frequency - normal (juveniles), healing facilitation (wounds, surgical incisions) * Reduced shed frequency - reduced feeding and growth * Bred morphs or phenotypes - amelanistic partial albinos, anerythristic partial albinos (lack reds and yellows), “snows/blizzards” (homozygous recessive for both alleles), leucistics (white with blue eyes), piebalds, scaleless (scales limited to head and ventrum)

Answer 58

MUSCULOSKELETAL * Fractures - bites, doors/lids, falls, handling, head pinning, osteomyelitis, neoplasia * Spondylosis, kyphosis, lordosis - abscessation, ossifying spondylosis, osteomyelitis, trauma, fractures, congenital, neurologic * Deformities (shortened jawas, restricted orbits, domed skulls, arched necks, two-headed snakes) - improper incubation/gestation temp, inbreeding * Paresis/paralysis - spinal lesions (trauma, infection/abscessation, spondylosis, neoplasia

Answer 59

NEUROLOGICAL * Depression - head trauma, low temperatures, drug reaction, systemic illness, intoxication * Ataxia - toxins (cedar, phenolic cleaners, organophosphates, ivermectin), head trauma, hypothermia, spinal osteomyelitis, boid inclusion body disease (arenavirus), meningitis, encephalitis, thiamin deficiency (water snakes/fish diets), hypoglycemia, starvation, debilitation, hepatic encephalopathy, renal disease (dehydration, aminoglycoside administration), neoplasia, paramyxovirus infection * IBD - head tilt, opisthotonos, flaccid paralysis, disorientation, loss of righting reflex, inability to ingest food, death * Nutritional - Hypocalcemia (insectivores without supplementation), thiamin/biotin deficiencies linked to tremors and convulsions (piscivores without supplementation) * CNS tumors rare - reduced activity, incoordination, ataxia, convulsions, anorexia, death * Head tilts - head trauma, metabolic, unilateral ocular disease, sepsis, encephalitis, abscess, granuloma, neoplasia * Seizures/convulsions - septicemia, CNS abscessation, encephalitis (bacterial, viral, protozoal, helminth), head trauma, toxins, heat stroke, metabolic, neoplasia, thiamine deficiency

Answer 60

REPRODUCTIVE * Failure to breed - inaccurate sexing, inappropriate cycle, malnutrition * Infertile eggs- failure of copulation or sperm transportation * Failure to produce eggs - infection, blockage * Dystocia - obesity, nutrition, dehydration, primipara, “power-feeding”, large or abnormal eggs, improper temperatures, inactivity/inappropriate caging, lack of security, lack of laying/birthing site, oviductal infection, death of fetus, mass blocking egg/fetus, prolapsed oviduct * Always suspected if gravid female is acutely anorectic/lethargic * Stillbirth - same factors as dystocia, large snakes with inadequate space may accidentally crush/suffocate neonates * Follicular stasis (neither ovulate nor regress and associated with lethargy/anorexia) * Failure to hatch - inappropriate incubation temp or excessive variation, inappropriate humidity, fetal death, congenital abnormalities, egg infections, egg infertility

Answer 61

RESPIRATORY * Signs -anorexia, lethargy, nasal discharge, oral discharge, dyspnea, open-mouth breathing, abnormal posture (head/neck elevated), sneezing, wheezes, stridor, stertor, audible respiratory noise in relaxed snake (differentiate from normal - defensive hissing, more alert snakes may have increased sounds, nearing shed may also increase noise) * Oral/nasal discharge - respiratory, stomatitis, mix; pneumonia (bacterial, fungal, viral, parasitic), pulmonary neoplasia is rare * Dyspnea (open mouth breathing) - occluded nostrils, caseous debris, foreign body, intraoral mass, tracheal granuloma or chondroma, hyperthermia, toxins/irritants (smoke), drowning, severe gastrointestinal enlargement * Epistaxis rare - skull, oral or body trauma

Answer 62

SYSTEMIC * Weakness, anorexia, and weight loss can be general signs of disease * Inappropriate husbandry * Consider normal species behavior and diet * Maladaptation syndrome - failure of wild caught snakes to adjust in captivity * Weight gain - excessive feeding, inadequate activity, growing, gravid, constipation, coelomic distension * Coelomic distension - gastrointestinal disease, organomegaly, neoplasia, reproductive (60-70% of SV), obesity, transudates/exudates * Ascites/coelomitis - hypoproteinemia, abnormal hepatic function, renal disease, cardiac disease, septicemia, neoplasia * Acute mortalities (uncommon compared to more chronic) * Traumatic injuries, burns, drowning * An aortic aneurysm has been reported in a burmese python after constricting its meal * **Use caution when handling dead venomous snakes**

Answer 63

Contrast * Barium sulfate provides excellent detail and is inexpensive, but can result in intestinal obstruction if a large volume is used or stays for a long time -\> massage out with gentle pressure or saline lavage at conclusion of study * Alternatives to barium should be considered when perforations or adhesions are suspected, although this has not been evaluated in snakes (peritonitis in mammals) * Iodinated contrast agents have faster transit time: * Ionic (diatrizoate, Gastrografin) is hyperosmotic/draws interstitial fluid and not recommended in young, dehydrated, renal compromised patients or increased risk of aspiration * Nonionic (iohexal, Omnipaque) have lower osmolarity * Variable transit time - ectotherms, species differences, environment, season, food, etc * Published transit time studies for ball pythons (small intestinal transit time of 50.82+/- 12.34 hours) and bearded dragons * Keep at optimal temperature * Contrast should be warmed to body temperature * Suggested dose of 5-20 mL/kg contrast, should not exceed volume you would tube feed * 25 mL/kg barium administered in ball python study (distended stomach) * 4 ball pythons regurgitated in study * Double contrast studies for more mucosal detail * Retrograde studies- colon, cloaca; advance flexible catheter into distal colon and administer contrast until resistance encountered (potential complication of contrast in ureters or kidneys, so avoid barium) * Endoscopic evaluation superior for mucosal disease

Answer 64

Vipera ursinii rakosiensis Dystocia, problems with shedding, Ophionyssus natricis

Answer 65

Cardiac blood supply * Myocardium receives oxygen from both coronary circulation and venous blood held within the chambers * Importance of coronary artery questioned in one study in South American rattlesnakes (Crotalus durissus): no change in heart rate, blood pressure, or ECG tracings after ligation of coronary artery- no myocardial necrosis on necropsy but not long term study so theory is that this blood supply may become more important in periods of hypoxia or digestion as is seen in some fish (rainbow trout) Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77.

Answer 66

Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77. Neuroanatomy * Sympathetic innervation * Glossopharyngeal and spinal nerves * Causes positive inotropic and chronotropic effects * Epinephrine- positive inotrope * both sides of heart respond (unlike chelonians) * atria respond more vigorously than ventricle * Parasympathetic * Vagus nerve * Negative inotropic and chronotropic responses * Acetylcholine shown to be major parasympathetic neurotransmitter in heart and pulmonary vasculature- antagonized by atropine sulfate * Atria respond more vigorously to acetylcholine than ventricles * Pacemaker * In walls of sinus venosus * No purkinje fibers extending into ventricle as they do in mammals * Arrangement of muscle fibers accounts for timing of cardiac contraction and organization of systole and diastole- similar conduction to what exists in embryonic mammals

Answer 67

Blood flow and shunting * Body -\> sinus venosus -\> right atrium -\> cavum venosum -\> cavum pulmonale -\> pulmonary artery -\> lungs -\> Left atrium -\> cavum arteriosum -\> cavum venosum -\> right aorta/left aorta -\> body * This flow pattern facilitates carbon dioxide elimination in the lung, minimizes ventilation-perfusion mismatching, and improves systemic oxygen transport and myocardial oxygenation * Little is known about the cardiac shunting in snakes * Pythonidae have very little intracardiac shunting as compared to other snakes * Echo shows that atrioventricular valves in pythons descend deep into the ventricle during ventricular filling and thereby greatly reduce the communication between the systemic (cavum arteriosum) and pulmonary (cavum pulmonale) ventricular chambers during diastole * Crotalids * Do not possess pressure separation between systemic and pulmonary arteries- large right-to-left cardiac shunts at low temps are seen- during theses, blood flowing from right atrium fills cavum venosum of ventricle tehn is ejected directly through aortae instead of the pulmonary artery, bypassing the lungs * Advantage of right-to-left shunt during apnea: * During apnea can save cardiac energy, “metering lung oxygen stores, reducing carbon dioxide flux into the lung, reducing plasma filtration into the lung, facilitating warming, triggering hypometabolism, and facilitating stomach acid secretion and digestion * Apnea, increase in parasympathetic tone, bradycardia, and increase in pulmonary resistance- decrease in pulmonary blood flow, increase in right-to-left shunting of blood to aortae * Ventilation, decrease in parasympathetic tone, tachycardia and decrease in pulmonary resistance- lessens right-to-left shunt and allows an increase in pulmonary blood flow Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77.

Answer 68

Physiology-blood pressure * Typical systemic pressure in aortae range from 50-60mmHg (systolic) to 40-50mmHg (diastolic) in the snake * Arboreal- highest blood pressure- systemic (40-70mmHg) * Aquatic- lowest pressures (20-30mmHg) * Terrestrial is something in between * Compensation * Snake has head-up orientation gravity reduces venous return, cardiac filling, cardiac output, and blood pressure to cranial regions of body- hypotension triggers physiologic responses including vasomotor adjustments and tachycardia to normalize BP * Poor compensation- olive sea snake- does not alter blood pressure while in water but if snake is removed from water body cannot adapt to postural changes very well- if held head-up vertical position out of water, blood pressure at the head falls to 0mmHg * Abrupt hypertension often occurs while snakes are killing and ingesting prey * Temp changes between 18-33C can alter blood pressure in black racer but not in tiger snake * Higher systemic pressure maintained by pythonidae b/c don’t have shunting due to anatomy of heart- allows for high systemic pressure necessary for high metabolic needs such as large meal digestion Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77.

Answer 69

Neuroendocrine * Two main pressor systems- play role in blood pressure regulation * Alpha-adrenergic system * Catecholamines and acetylcholine * Catecholamines stimulate heart through beta-adrenoceptors, causing positive inotropic and chronotropic effects * Acetylcholine acts as a negative inotropic and chronotropic agent on the heart * Renin-angiotensin system * Angiotensin II will increase blood pressure by stimulating catecholamine release, promoting sodium chloride reabsorption in kidneys, promoting potassium excretion by kidneys, stimulating arterial constriction, stimulating arginine vasopressin secretion by pituitary gland, stimulating aldosterone secretion by adrenal gland * Argenine vasopressin increases blood pressure by causing constriction of capillaries and arterioles * ACE-inhibitor like captopril has been shown to lower BP in snakes * Bradykinin has positive inotropic and chronotropic effects on heart and peripheral vessels * Substance P can cause decrease in blood pressure and subsequent increase in cardiac output * Histamine has been shown to be a positive chronotrope in pythons after a meal Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77.

Answer 70

Diseases * Most common etiology is infectious * Secondary to systemic illness common (viral, bacterial, fungal, and protozoal) * Virus: eosinophilic intracytoplasmic inclusion bodies consistent with inclusion body disease found in cardiac myocytes in an amazon tree boa * Systemic bacterial infections: septicemia, microemboli, see heart, most commonly gram negative pathogens, infect cardiac muscle or form vegetative lesions * Valvular lesions can lead to valvular insufficiency and heart failure * Systemic mycobacterial infection affected myocardium in Assam trinket snake * Chlymydophila causing granulomatous pericarditis and myocarditis in puff adders and emerald tree boas * Systemic fungal diseases- myocarditis: Ophidiomyces ophidiicola- snake fungal disease- lymphoplasmacytic to lymphohistiocytic inflammation in internal organs * Parasite: protozoal myocarditis- bushmaster with sarcocystis sp. * Microfilaria Macdonaldium oschei can infect snakes though mosquito or mite vector and microfilaria are typically incidental finding in caudal vena cava and renal veins * Visceral helminthiasis- vascular thrombosis * Aortic plaques and aneurysms associated with parasitic invasion of aortic wall in amethyst python * Congenital * Bifid ventricle in ball python * Ectopic cordis in rainbow boa * Incomplete development of atriovetnrcular valves in ball python * Metabolic derangement * Renal disease- metabolic acidosis, hyperkalemia- negative inotropic effects a nd life-threatining arrhyhtias * Hyperuricemia during renal failure w/ soft tissue mineralization * Nutritional * Arteriosclerosis and atherosclerosis reported * Recent study found a relationship between cardiovascular disease and obesity * Obese found to die at younger age with aortic aneurysm, ventricular aneurysm, medial calcification of arteries * Other * Vascular aneurysms * Undefined cardiomyopathy in mole king snake- fibroblast prolideration and replacement of myocardial fibrils * Multiple other singe case reports of necrosis or cellular infiltrates * Trauma (phlebotomy, etc) * DIC caused by bacterial septicemia or hyperthermia * Neoplasia- hemangioma, fibrosarcoma, rhabdomyosarcoma Bogan Jr, J. E. (2017). Ophidian cardiology—a review. *Journal of Herpetological Medicine and Surgery*, *27*(1-2), 62-77.

Answer 71

* Vit D3 – From diet or photosynthesized: * 7-dehydrocholesterol in skin converted to pre-vitamin D3 via exposure to UVB radiation. * Most effective wavelength for this conversion ~297 nm. * Precursor becomes thermally isomerized over several days to cholecalciferol (vit D3). * Then binds vit D binding protein, is hydrolyzed in blood to 25-hydroxycholecalciferol (25-OH-D3), considered storage form of vit D. * Then in kidney, next hydroxylation yields bioactive calcitriol 1,25-dihydroxycholecalciferol (1,25-OH-D3), regulates Ca and P absorption (regulated by parathyroid hormone). * Functions * 25-OH-D3 acts as a hormone, regulates cell division by regulation of cell cycling and proliferation, differentiation, apoptosis. * 1,25-OH-D3 acts as regulatory mechanism controlling Ca level in blood serum. * Inversed Ca:P ratios in reptiles – vit D deficiency, renal disease, or dietary imbalance. * Snakes – Corn snakes capable of de novo vit D synthesis. Ball pythons, no relationship between UVB and vit D concentrations found (70 day exposure). Bos, J. H., Klip, F. C., & Oonincx, D. G. (2018). Artificial ultraviolet b radiation raises plasma 25-hydroxyvitamin d3 concentrations in Burmese pythons (Python bivittatus). *Journal of Zoo and Wildlife Medicine*, *49*(3), 810-812. Abstract: Deficiency of vitamin D can contribute to health complications that present as metabolic bone disease. The aim of this small-scale study was to determine if a high UVb irradiance would affect an increase in plasma vitamin D₃ concentrations in Burmese pythons (*Python bivittatus*). There have been inconsistent results throughout the literature concerning the usefulness of UVb radiation regarding vitamin D₃ synthesis. Blood samples of four healthy Burmese pythons were taken at day 0 and day 310. After the first blood sample was taken, an Arcadia Superzoo T5 ASZ01 lamp was fitted in the enclosure. For 310 days, the pythons were exposed to UVb radiation. Blood plasma vitamin D₃ concentrations were considerably higher after UVb exposure. This study indicates that a period of 10 mo of UVb exposure can result in an increased vitamin D₃ status in Burmese pythons. Answering whether these elevated levels have health benefits for Burmese pythons (and possibly other snake species) requires further studies.

Answer 72

* Results * LRR not observed in any snake for 10 mg/kg * LRR observed in 5/8 snakes with 20 mg/kg and 8/8 for 30 mg/kg * Time to LRR was shorter for 30 mg/kg, but time to RRR did not differ significantly * RR did not differ significantly at any point * HR was lower after LRR and then got faster again right before RRR * Phase 2: Mean tactile pressure to elicit response in unanesthetized snakes was 16.9 +/- 14.3 * Phase 3: Purposeful movement was not elicited by tactile stimulation testing in any of the 8 snakes at 10 and 20 minutes after LRR * Started to elicit response at 30 minutes in some snakes, all snakes by 50 minutes * The mean tactile pressure required to elicit purposeful movement was significantly greater than that at baseline at 10, 20, and 30 minutes after LRR but did not differ significantly from baseline at LRR and at 40, 50, and 60 minutes after LRR. * Discussion * 30 mg/kg alfaxolone was effective in all snakes * Dose was not given in the cranial portion of the body because of vital structures, may have needed a higher dose due to it being in the caudal half * HR may be used to assess anesthetic depth with this specific drug protocol * Anesthetic depth was greatest between 10 and 30 minutes based on lack of response to tactile stimulus Strahl-Heldreth, D. E., Clark-Price, S. C., Keating, S. C., Escalante, G. C., Graham, L. F., Chinnadurai, S. K., & Schaeffer, D. J. (2019). Effect of intracoelomic administration of alfaxalone on the righting reflex and tactile stimulus response of common garter snakes (Thamnophis sirtalis). *American journal of veterinary research*, *80*(2), 144-151. OBJECTIVE T**o determine the intracoelemic (ICe) dose of alfaxalone required to induce loss of righting reflex (LRR) in garter snakes (Thamnophis sirtalis) and to evaluate the tactile stimulus response in unanesthetized and alfaxalone anesthetized snakes.** ANIMALS 8 healthy mature garter snakes. PROCEDURES During the first of 3 phases, snakes received each of 3 doses (10, 20, and 30 mg/kg) of alfaxalone, ICe, with a 2-week washout period between treatments. Times to LRR and return of righting reflex were determined after each dose. During phase 2, unanesthetized snakes underwent tactile stimulation testing with Semmes-Weinstein monofilaments once daily for 3 consecutive days to determine the baseline tactile pressure required to elicit purposeful movement. During phase 3, snakes were anesthetized with alfaxalone (30 mg/kg, ICe), and the tactile pressure required to induce purposeful movement was assessed at predetermined times after LRR. RESULTS Intracoelomic administration of alfaxalone at doses of 10, 20, and 30 mg/kg induced LRR in 0, 5, and 8 snakes, respectively. **For snakes with LRR, median time to LRR following the 30-mg/kg dose (3.8 minutes) was significantly shorter than that following the 20-mg/kg dose (8.3 minutes); median time to return of righting reflex did not differ between the 2 doses.** Mean ± SD tactile pressure that resulted in purposeful movement in unanesthetized snakes was 16.9 ± 14.3 g. When snakes were anesthetized, the mean tactile pressure that resulted in purposeful movement was significantly increased from baseline at 10, 20, and 30 minutes after LRR. CONCLUSIONS AND CLINICAL RELEVANCE **Results suggested ICe administration of alfaxalone might be effective for anesthetizing garter snakes.**

Answer 73

* Sevoflurane - Gas avoidance behavior during induction * Longest recovery time to extubation AND longest return of pressure response * Isoflurane = longest time to return of RR * Desflurane - Quickest loss of RR; Shorter time to intubation compared to isoflurane * NOT deep enough for intubation in 4 out of 12 snakes (persistent jaw tone) * No significant difference in time to loss of pressure response, HR, Resp R * No snakes died during the study **Take home**: Isoflurane and sevoflurane produced reliable anesthesia with predictable RR loss and depth, desflurane did not and is not recommended in rattlesnakes Kane, L. P., Chinnadurai, S. K., Vivirito, K., Strahl-Heldreth, D., & Allender, M. C. (2020). Comparison of isoflurane, sevoflurane, and desflurane as inhalant anesthetics in prairie rattlesnakes (Crotalus viridis). *Journal of the American Veterinary Medical Association*, *257*(9), 945-949. **OBJECTIVE:** To characterize induction and recovery characteristics of 3 commonly used inhalant anesthetics in prairie rattlesnakes (*Crotalus viridis*): isoflurane, sevoflurane, and desflurane. **ANIMALS:** 12 healthy adult prairie rattlesnakes. **PROCEDURES:** In a randomized crossover design, snakes underwent anesthetic induction with 5% isoflurane, 8% sevoflurane, or 18% desflurane, with a washout period of ≥ 7 days between anesthetic events. Anesthetic depth parameters were recorded throughout induction and recovery, including time to loss and return of righting reflex, muscle tone, ability to intubate, response to pressure, and time to return to spontaneous respiration. Every 5 minutes throughout the anesthetic procedures, heart rate, respiratory rate, and percentage expired anesthetic gas were recorded. **RESULTS:** No snakes died during the study. Sevoflurane anesthesia resulted in anesthetic gas avoidance behavior in snakes during induction and had the significantly longest recovery time to extubation and time to return of pressure response, compared with the other inhalant anesthetics. Anesthesia with isoflurane resulted in a significantly longer time to return of righting reflex, compared with sevoflurane or desflurane. No significant difference was noted in time to loss of pressure response among the 3 anesthetic gases. Desflurane anesthesia resulted in the significantly quickest loss of righting reflex among the anesthetic protocols; despite this, 4 of 12 desflurane anesthetized snakes did not achieve an anesthetic plane deep enough for intubation. **CONCLUSIONS AND CLINICAL RELEVANCE**: Isoflurane and sevoflurane, but not desflurane, inhalation anesthesia resulted in consistent and predictable loss of righting reflex and induction of anesthesia deep enough to allow intubation in snakes.

Answer 74

* 12 bullsnakes used to compare the physiologic and anesthetic effects, and differences, between two intramuscular drug protocols * Snakes anesthetized for radiotelemetry study * Injected IM with 10 mg/kg butorphanol, followed by either 20 mg/kg alfaxalone or a combination of 0.5 mg/kg midazolam, 0.05 mg/kg dexmedetomidine, and 5 mg/kg ketamine (MDK). * No signs of sedation were appreciable 1 hour post butorphanol administration * All bullsnakes in the alfaxalone group responded to surgical stimulation and required iso * MDK group achieved surgical plane of anesthesia and did not require iso * MDK group was given reversals * MDK group recovered significantly faster than alfaxalone group (but also did not receive any iso) * Body temperature did not differ between groups Use of Alfaxalone or Midazolam–Dexmedetomidine–Ketamine for Implantation of Radiotransmitters in Bullsnakes (Pituophis catenifer sayi). *Journal of Herpetological Medicine and Surgery*, *28*(3-4), 93-98. Abstract The objective of this study was to compare the physiologic and anesthetic effects, and differences, between two intramuscular drug protocols in adult bullsnakes (Pituophis catenifer sayi); the bullsnakes were being anesthetized for a radiotelemetry study. Free-ranging bullsnakes were injected IM with 10 mg/kg butorphanol, followed by either 20 mg/kg alfaxalone or a combination of 0.5 mg/kg midazolam, 0.05 mg/kg dexmedetomidine, and 5 mg/kg ketamine (MDK). After administration, muscle tone, response to stimuli, and jaw tone were evaluated before endotracheal intubation and surgical stimulation to implant coelomic transmitters. If a bullsnake responded to stimulation induced by surgical preparation, or noxious stimuli induced by the surgical procedure, isoflurane was administered to maintain a surgical plane of anesthesia. Heart rate, sedation depth, esophageal temperature, end-tidal CO2, respirations, time to spontaneous ventilation, extubation, return of righting reflex, and return of spontaneous movement were recorded. Assisted ventilation was initiated if bradypnea (,2 breaths/min) or apnea occurred. Six bullsnakes were evaluated in each group, for a total of 12 bullsnakes. The MDK group was reversed with 0.5 mg/kg atipamezole and 0.02 mg/kg flumazenil IM. All alfaxalone-treated bullsnakes responded to surgical stimulation with movement and required anesthetic maintenance with isoflurane, whereas none of the MDK bullsnakes required inhalant anesthesia. Bullsnakes anesthetized with MDK recovered significantly faster after reversal than bullsnakes in the alfaxalone group. MDK produced a satisfactory level of anesthesia for a minor surgical procedure in bullsnakes, whereas alfaxalone did not. Additional injectable (beyond butorphanol) or inhalant anesthetic agents are recommended for surgical procedures when using alfaxalone.

Answer 75

**Take home points:** * Midazolam at 1-2 mg/kg IM (cranial third of the snake) provided moderate- profound sedation and muscle relaxation for 3-5 days with peak effect at 60 minutes * Side effects of midazolam- reduced HR, less commonly paradoxical excitation * Recommend dose of 1 mg/kg or lower when combining with other anesthetics * Expect re-sedation with flumazenil given at 0.08 mg/kg IM * Adverse effects: one snake had agitation, restlessness, hypersalivation, frequent open mouth breathing from 30 min to 8 hours after the 1 and 2 mg/kg midazolam injections (less pronounced after the 1 mg/kg dose) * Paradoxical excitation- possible pathophys- central anticholinergic effects, alteration of the serotonergic balance leading to rage/aggression, individual mutations of the GABA receptors Larouche, C. B., Beaufrère, H., Mosley, C., Nemeth, N. M., & Dutton, C. (2019). Evaluation of the effects of midazolam and flumazenil in the ball python (Python regius). *Journal of Zoo and Wildlife Medicine*, *50*(3), 579-588. Abstract: The study objective was to evaluate the sedative, muscle relaxant, and cardiorespiratory effects of midazolam and flumazenil in the ball python (*Python regius*). Ten healthy adult female ball pythons were used in a randomized and blinded crossover trial evaluating the effects of two dosages (1 and 2 mg/kg intramuscular [i.m.] in the cranial third of the body). In a subsequent open trial, nine ball pythons received 1 mg/kg i.m. of midazolam followed by 0.08 mg/kg i.m. of flumazenil 60 min later. Heart rate, respiratory rate, temperature, and the level of sedation and muscle relaxation (using a semiobjective scoring system) were evaluated. There were **no significant differences between midazolam dosages for any of the parameters evaluated.** **Sedation scores were significantly increased compared with baseline from 15 min (1 mg/kg) and 10 min (2 mg/kg) postinjection up until 56 hr (1 mg/kg) and 72 hr (2 mg/kg) postinjection.** **Peak effect was reached 60 min postinjection**, with 60% of snakes (6/10) being unable to right themselves. **One snake developed paradoxical excitation with the 2 mg/kg dosage.** Heart rates were significantly lower than baseline from 30 min to 128 hr postinjection with both midazolam dosages. Respiratory rates were significantly lower than baseline at four time points, with the highest dosage only: 15, 45, 60 min, and 8 hr postinjection**. Flumazenil resulted in reversal of sedation and muscle relaxation in all snakes within 10 min of administration. However, resedation was evident in all snakes 3 hr after reversal.** Midazolam administered at 1 and 2 mg/kg i.m. provides a moderate to profound, although prolonged, sedation and muscle relaxation in ball pythons. **Flumazenil reverses the effects of midazolam in ball pythons, but its duration of action at the evaluated dosage is much shorter than midazolam, leading to resedation.**

Answer 76

* Transcutaneous oxygen monitoring used near-infrared spectroscopy sensors to assess regional oxygen saturation (rSO2) * Measure a mixture of arterial, venous and capillary blood within tissues (ratio of 20:75:5) * Used in human medicine to assess cerebral oxygenation during anesthesia * Respiratory rate decreased between breathing room air and breathing oxygen, but otherwise no changes in oxygen parameters between phases * rSO2(half) and rSO2(liver) both showed strong positive associations with PvO2 (stronger than SPO2 and PvO2 correlations) * rSO2 = noninvasive metaparameter * Influenced by many variables- oxygenation, regional perfusion, metabolism (influenced by both oxygen supply and demand) * Anesthetic drugs have been shown to decrease oxygen demand * Have not been shown to be affected by low oxygen saturation levels * PvO2 stronger association with the liver sensor could have been due to hepatic parenchyma larger blood supply compared to the other organs (where the half way point sensor was placed) * SpO2 had the weakest association with PvO2 * Relies on pulsatile flow, limited usefulness in reptiles * Was placed over the heart- unknown if the readings were being taken from arterial, venous, mixed blood * PvO2 decreased between phases 1 and 2 despite oxygen administration Cushing, A. C., Smith, C. K., Ramsay, E. C., Nelson, S., & Giori, L. (2020). Transcutaneous oxygen monitoring in louisiana pine snakes (pituophis ruthveni). *Journal of Zoo and Wildlife Medicine*, *50*(4), 874-878. Abstract: Hypoxic physiological states may occur during anesthetic events of snakes but accurate monitoring of oxygenation is challenging. Oxygenation levels of nine Louisiana pine snakes (Pituophis ruthveni) were assessed using transcutaneous regional oxygen saturation (rSO2) at the level of the liver (rSO2Liver) and at the halfway point of the body (rSO2Half ). Reflectance pulse oximetry measured SpO2, with a sensor overlying the heart. Values were compared with the venous partial pressure of oxygen (PvO2). Measurements were taken during four phases, simulating an anesthetic event: phase 1, breathing room air; phase 2, while supplied with supplemental oxygen via face mask; phase 3, during ketamine and dexmedetomidine sedation; and phase 4, after receiving atipamezole. There were no significant changes in any oxygenation parameters between concurrent phases, but respiratory rate significantly decreased (P 1⁄4 0.02) between phases 1 and 2. Strong positive associations were found between both rSO2Liver and rSO2Half when compared with PvO2 irrespective of phase (r 1⁄4 0.72, r 1⁄4 0.63 respectively), but not with SpO2 (r 1⁄4 0.3). Strength of correlation varied with each phase but was uniformly strongest for rSO2Liver. The measurement of rSO2 appears superior compared with traditional pulse oximetry for assessing oxygenation levels of snakes.

Answer 77

* Alfaxalone: neuroactive synthetic steroid * Enhances neuronal cell membrane chlorine ion transport via interaction with cell surface y-aminobutyric acid A receptors to induce sedation and anesthesia * Apnea and prolonged recovery with high doses in reptiles, reactive to stimulation with low doses * No adverse effects, no tissue damage at injection sites * SC allowed larger volume with comparable induction time to IM * Both AM and DM: similar depth of sedation, successful intubation and blood draw, HR and RR decreased significantly * AM: * shorter time to first effect and loss of jaw tone * longer duration of loss of righting reflex (no antagonist) * longer time to recovery * More snakes were reactive to superficial pain stimulation * Majority had spontaneous mouth opening/chewing behavior * DM: * greater decrease in HR and RR * Increase in tidal volume - possibly compensating for decreased RR * Transient periods of apnea **Takeaways:** SC alfaxalone (5 mg/kg) + midazolam (0.5 mg/kg) or dexmedetomidine (0.05 mg/kg) + midazolam (0.5 mg/kg) resulted in sufficient sedation for tracheal intubation and blood sample collection in healthy juvenile ball pythons * Self-limiting apnea * Both protocols induced significant decreases in RR and HR, more profound with DM * DM can be reversed - faster recovery Yaw, T. J., Mans, C., Johnson, S., Bunke, L., Doss, G. A., & Sladky, K. K. (2020). Evaluation of subcutaneous administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius). *Journal of the American Veterinary Medical Association*, *256*(5), 573-579. OBJECTIVE To evaluate SC administration of alfaxalone-midazolam and dexmedetomidine-midazolam for sedation of ball pythons (Python regius). ANIMALS 12 healthy juvenile ball pythons. **PROCEDURES** In a randomized crossover study, each snake was administered a combination of **alfaxalone (5 mg/kg [2.3 mg/lb]) and midazolam (0.5 mg/kg [0.23 mg/lb])** and a combination of **dexmedetomidine (0.05 mg/kg [0.023 mg/lb]) and midazolam (0.5 mg/kg)**, **SC**, with a washout period of at least 7 days between protocols. Respiratory and heart rates and various reflexes and behaviors were assessed and compared between protocols. Forty-five minutes after protocol administration, sedation was reversed by SC administration of flumazenil (0.05 mg/kg) alone or in combination with atipamezole (0.5 mg/kg; dexmedetomidine-midazolam protocol only). Because of difficulties with visual assessment of respiratory effort after sedative administration, the experiment was repeated for a subset of 3 ball pythons, with plethysmography used to assess respiration. RESULTS Both protocols induced a similar level of moderate sedation with no adverse effects aside from transient apnea. Cardiopulmonary depression was more profound, but time to recovery after reversal was significantly shorter, for the dexmedetomidine-midazolam protocol than for the alfaxalone-midazolam protocol. Plethysmographic findings were consistent with visual observations and suggested that snakes compensated for a decrease in respiratory rate by increasing tidal volume amplitude. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that both protocols induced clinically relevant sedation in ball pythons and should be useful for minor procedures such as venipuncture and diagnostic imaging. However, caution should be used when sedating snakes with compromised cardiopulmonary function.

Answer 78

**Organism**: Cryptosporidium * Sole genus within the subclass Cryptogregaria, class Gregarinomorphea, phylum Apicomplexa * NOT an obligate intracellular parasite as previously thought- may be able to complete its life cycle outside of the host cell * Now classified as intracellular/extracytoplasmic (colonizes the area between the phospholipid bilayer of the enterocyte) * Total 38 species formally named, 40 genotypes found but not yet named * Of these, FOUR infect reptiles (these have not been found to be zoonotic) * Gastrotropic * *C. serpentis* primarily pathogen of snakes (also been found in geckos, desert monitors, nile monitors, savannah monitors with gastritis * Two types * A: infects primarily snakes * B: infects primarily lizards * *C. testudinis-* isolated from tortoise species and a ball python * Enterotropic * *C. varanii*- primarily infects lizards, but has been recovered from snakes with proliferative enteritis * *C. ducismarci*- isolated from an asymptomatic ball python, typically associated with disease in chelonians * Non-pathogenic in reptiles: C. baileyi, C. muris, C. parvum (mouse and bovine genotypes) - thought to be pseudoparasites/pass-through parasites of prey * Important to note some of these pseudoparasites ARE zoonotic **Disease:** * Life Cycle * C. serpentis infections- merogony, gametogony, oocyst development happen in the brush border of the gastric epithelial cells * Host response = mucosal hypertrophy, edematous longitudinal rugae, increased mucus production, mucosal petechiae, brush border hemorrhage * Transmission * Oocyst transmission- direct via fecal/oral or indirect via contaminated environment * Spread the fecal-oral route, oocysts periodically shed during infection * Snakes that eat other snakes (ophiophagy) at higher risk * Possible vertical transmission * Two manifestations of disease * Subclinical- can either clear on their own or stay in a carrier state and shed oocysts into the environment persistently; infection can worsen and become clinical over time * Clinical- signs attributed to gastric mucosal hypertrophy → chronic regurgitation, lethargy, anorexia * Can hypertrophy to the point of causing a visible/palpable bulge * Why subclinical vs. clinical presentation? * Environmental stressors * Oxidative stress- selenium deficiency? * Concurrent infection- ie immunosuppressive viral infections * Using info known about mammal crypto… * Clinical disease can range from subclinical to severe depending on the species of parasites + age/immunological status of host * Young mammals more susceptible (most reports in mammals \< 1 month old) and immunocompromised adults * Clinical signs- watery, cholera-like diarrhea, anorexia, weight loss, dehydration, abdominal discomfort * In mammals- colonizes most regions of GI tract, most commonly isolated in the lower jejunum and ileum **Prevalence**: * depends on the location and diagnostic used (some underestimated because just using acid fast stain on feces) * Study in Italy- 4.8- 35% based on IFA screening of feces from asymptomatic snakes; Thailand- 24% from asymptomatic snakes * Similar prevalence in US/Brazil * Wild populations- 26% by fecal PCR Bogan Jr, J. E. (2019). Gastric Cryptosporidiosis in Snakes, a Review. *Journal of Herpetological Medicine and Surgery*, *29*(3), 71-86.

Answer 79

**Diagnostics**: Antemortem * Note that reptiles shed way less oocysts than mammals (ie 50,000 oocysts/ml vs. up to 8 billion/ml in cows with C. parvum) * Easiest sample to evaluate = fresh feces or vomitus/regurgitate * Best to evaluate LARGE fecal samples- \>0.41% of snake’s body weight increase chances of finding oocysts * Alternative method = cloacal swab * Serum for antibody testing- potential for misclassification * Can take over 30 days for ab to be detected after exposure * Test is not specific for C. serpentis * Immunosuppressed snakes may not be capable of mounting an immune response → high false-negative rate * Authors do NOT recommend serum antibody testing * **MOST SENSITIVE SITE FOR GASTRIC CRYPTO = STOMACH** * Gastric lavage = Flexible tube introduced into the stomach, 5-10 ml saline infused, massage the stomach and then aspirate the fluid * Alternative to gastric lavage = equine uterine culture swab used to swab the stomach * Lubricate the outer PVC of the tube, introduce into the stomach, advance the swab through the PVC sheath and rotate several times against the gastric mucosa * Recommend collecting samples 3 days after feeding * Biopsy of the stomach = most sensitive technique for detecting C. serpentis * Surgical or endoscopic, 3 days after feeding, 15-20 biopsies * Once gastric sample collected… * Simplest test = direct smear with Wright-Giemsa or similar stain * Cryptosporidium oocysts = circular, between 4-8 um diameter * False negatives common (due to low oocyst concentration) * Acid fast staining * Twice as sensitive as direct smear * Minimum concentration to detect oocysts = 75,000/ml * Oocyst morphology not sufficient to speciate Crypto * IFA- minimum oocyst concentration- 4,000/ml * For feces- more than 2x more likely to detect oocysts than acid fast, 5x more likely than direct smear * For gastric lavage- no advantage over acid fast * False positives common because it cross reacts with other species of crypto * ELISA- not recommended by authors because IFA and PCR have been shown to be more sensitive (minimum concentration of oocysts- 17,500/ml) * **PCR = most sensitive** * Can detect samples at concentrations of 40 oocysts/ml * DNA sequencing needed because the PCR not specific for C. serpentis * Basically, all diagnostics have potential for false negatives AND because shedding is intermittent, recommended to collect samples days-weeks apart * Authors use minimum level of oocyst that are reliably detected rather than sensitivity as a percentage to compare the tests (see numbers above)

Answer 80

**Treatment**: * No treatment has been shown to be completely effective * Nitazoxanide = only drug approved by the FDA for treating crypto in humans but has limited effectiveness * Most drugs used to treat other protozoan infections have been shown to be ineffective at treating crypto * Treatments used in humans/other mammals not recommended/proven to work in reptiles: * Rifaximinem nitazoxanide * Halofuginone lactate- used in cattle- when tried in snakes with C.serpentis → parasite not eliminated and led to liver necrosis * Hyperimmune bovine colostrum = colostrum from dairy cows immunized during gestation with C. parvum antigen * Evaluated in reptiles with mixed results * Only available in research settings * Suggested dosing- 1 ml/kg/week for 6-7 weeks * Drug with the most promise that is commercially available = paramomycin * Aminoglycoside * Mixed results in reptiles * Have seen improvement but then recurrence in tortoises and geckos, gila monsters * Clearance when used in bearded dragons, single case of king cobra * Higher doses likely result in higher gastric and intestinal lumen drug concentrations * Likely more successful early in the disease before hypertrophy makes it harder for drugs to penetrate into the mucosa * Contraindicated in animals with gastric ulcerations because of increased absorption → ototoxicity, nephrotoxicity, pancreatitis in mammals, use with caution **Future possible treatments**: * Clofazimime = antimycobacterial agent used in humans * Imidazopyrazines and pyrazolopryidines * Non-traditional compounds- essential oils, selenium, curcumin- have been used in mammals **Environmental disinfection**: * Prevention = proper biosecurity and hygiene * Feeding thawed frozen prey reduces chance of spread * Oocysts inactivated at 5F, -15C AND above 133F, 56C * Recommendations for disinfectants * Ammonia at high levels is effective, but not recommended due to possible safety concerns at higher concentrations * Hydrogen peroxide at least 6%, 20 min contact time **Recommended case management per authors**: * ISOLATE possible cases with proper quarantine techniques * Snakes diagnosed with gastric cryptosporidiosis and showing clinical signs should be euthanized * Snakes without clinical signs * Screen all other snakes with PCR analysis using gastric lavage or gastric swabbing 3 days after feeding * Repeat minimum monthly for 3 months with 3 negative tests * Positive animals should be confirmed with gastric visualization and biopsies * Biopsies should be sent for histo and PCR * Once confirmed, consider treatment * 360 mg/kg paromomycin twice/week for 6 weeks * Difficult to monitor treatment success because many tx only decrease the degree of oocyst shedding and do not actually clear the infection * If snake is singly housed- periodic gastric lavage or swab for PCR recommended plus monitoring for any clinical signs * Before removing a snake from quarantine- evaluate oocyst shedding after treatment with cloacal swabs (PCR) every 2 months for 6 months * If no evidence of crypto shedding- then snake should be immunosuppressed * Recommend 2-4 mg/kg dex SP SQ * Risks of immunosuppression = increase in shedding of other pathogens (ie Salmonella) * Should be monitored after immunosuppression for development of clinical signs * Recommend gastric lavages/swabs for PCR over at least 1 year before returning to collection; can also confirm on gastric endoscopy/biopsies * If negative again, can be put back into collection but continually monitored and screened for C. serpentis on a regular basis Bogan Jr, J. E. (2019). Gastric Cryptosporidiosis in Snakes, a Review. *Journal of Herpetological Medicine and Surgery*, *29*(3), 71-86.

Answer 81

* Diastole - systemic and pulmonary blood flows partially separated by interventricular septum * Deoxygenated blood from RA flows into cavum venosum and cavum pulmonale * Oxygenated blood from left atrium flows into cavum arteriosum * Systole - muscular ridge moves cranially * Deoxygenated blood expelled from cavum pulmonale into pulmonary trunk * Oxygenated blood flows from cavum arteriosum to cavum venosum and expelled into 2 aortic arches * Muscular ridge regulates cardiac shunting * Anoxia = right-to-left shunt * Digestion = left-to-right shunt * Pythons - muscular ridge well developed, forms almost complete ventricular septum, functionally dividing ventricle into 2 chambers * Left and right atrial lengths differed significantly by sex - longer in females than males * With exception of LFS and TFS, cardiac variables positively correlated with BL and BM * LFS and TFS significantly correlated with BL but not with BM * Diameters of major vessels not correlated with BL or BM * Cardiac measurements cannot be accurately inferred from BL and BM in ball pythons Paillusseau, C., Gandar, F., Schilliger, L., & Chetboul, V. (2020). Two-dimensional echocardiographic measurements in the ball python (python regius). *Journal of Zoo and Wildlife Medicine*, *50*(4), 976-982.

Answer 82

* Presentation of a swelling caudal to the cloaca was similar in all six snakes and led to the clinical diagnosis of a cloacal scent gland impaction * No other systemic signs aside from obstipation * Infection (66.7%), neoplasia (16.7%), and mineralization (16.7%) of the glands were associated with the clinical impactions in 83.3% snakes * Colubrids, older snakes, and female animals over-respresented * Medical management often unrewarding or impossible * Surgical excision recommended * Introduction of a small probe, wax, or synthetic resin may help to better delineate the gland before resection recommended * Ligate gland as close as possible to proctodeum to remove all possible glandular tissue and allow histopath of excretory duct Couture, É. L., Lung, N. P., Lair, S., & Ferrell, S. T. (2018). Ophidian Cloacal Scent Gland Impaction and Surgical Excision: A Case Series in Six Different Snake Species. *Journal of Herpetological Medicine and Surgery*, *28*(3-4), 81-88.

Answer 83

Steeil, J. C., Hope, K. L., Evans, M., Peters, A., & Cartoceti, A. (2018). Multifocal Ophidiomyces ophiodiicola Infection in an Eastern Diamondback Rattlesnake (Crotalus adamanteus) without the Presence of Skin Lesions. *Journal of Herpetological Medicine and Surgery*, *28*(3-4), 76-80. * Ophidiomyces ophiodiicola – most infections in crotalids are found on the face and produce ulcerative dermatologic disease * This is the first case without skin lesions – presented as two subcutaneous masses, radiographs revealed additional granulomas within the lungs * An outbreak of SFD occurred in the facility the year before

Answer 84

* Ophidiomyces ophiodiicola * Ophidiomycosis * In eastern US timber rattlesnake populations & eastern massasauga- Severe, deep granulomatous dermatitis affecting mainly the face * Gravid & vitellogenic snakes → less severe infection vs. nonreproductive females * Gross presentation of ophidiomycosis in adults was consistent with previous reports, but c/s in neonates were subtle * Mortality of eastern massasauga neonates → rapid ( \>2 wk after birth) * In an O. ophiodiicola challenge study → adult cottonmouths had clinical signs in 50% of animals by day 45, longer than the neonates in this report * Suspected short course of infection & high mortality rate → assoc. w/ increased susceptibility in neonates * Wild adult eastern massasaugas → mortality rate \>90% * Time from infection to mortality is unknown * Subtle / absent c/s in neonates → diagnosis difficult * Retesting with qPCR 7 yr after the outbreak identified two O. ophiodiicola–positive neonates born to a negative female, which may be attributed to either a false negative result in the female or increased susceptibility to infection in neonates. * Mech. of transmission is not understood * Not transferred from dam to fetus in utero or during parturition→ occurs after birth * Recommended that wild snakes brought into a captivity are tested for O. ophiodiicola using qPCR * Neonates born to wild gravid females in captivity → immediately removed from female’s enclosure & tested for O. ophiodiicola regardless of female’s disease status * Individuals should be housed singly to prevent direct contact * PPE should be worn handling animals, and changed between individuals * Cages and equipment shared between animals should be cleaned with bleach to prevent disease transfer Britton, M., Allender, M. C., Hsiao, S. H., & Baker, S. J. (2019). Postnatal mortality in neonate rattlesnakes associated with ophidiomyces ophiodiicola. *Journal of Zoo and Wildlife Medicine*, *50*(3), 672-677.

Answer 85

* Review of neoplasia pathology records in 255 snakes at Zoo Atlanta over 21-year period * Evaluated by pathologist with no confirmatory tests performed * Neoplasia found in 37 of 255 snakes – 14.5% * Poorly differentiated sarcoma most common tumor type * Skin and SC most common (n=6), then bile duct and multiorgans (n=5), liver and kidney (n=4), skeletal muscle/spleen-splenopancreas/pancreatitc duct/ovary or oviduct (n=2), and brain/bone marrow/coelom/intestine (n=1) * 5 families: Viperidae (n = 19), Colubridae (n = 10), Elapidae (n =5), and Boidae (n =2), Pythonidae (n = 1) * 35 (83.3%) were malignant * 19 (54.3%) were mesynchymal AND 14 (40%) were epithelial origin * Some previous studies show similar results, others show epithelial more common in snakes * 11 out of 42 neoplasms (26.2%) had metastasis * Primarily to liver (n=7), then kidney, vasculature, adipose, intestines, ovary, skeletal muscle, bone, heart, and adrenal gland * 12.5% median annual neoplasm rate at Zoo Atlanta Page-Karjian, A., Hahne, M., Leach, K., Murphy, H., Lock, B., & Rivera, S. (2017). Neoplasia in snakes at zoo Atlanta during 1992–2012. *Journal of Zoo and Wildlife Medicine*, *48*(2), 521-524.

Answer 86

* Spontaneous tumors of GIT are uncommon in all animals with colonic adenocarcinomas reported in snakes, mostly colubrids * **Colubrids found to have highest incidence of neoplasia compared to other snake families** * Case report describing colonic adenocarcinoma in Amur rat snakes at Reserve Africaine de Sigean, France * **Colonic adenocarcinoma accounted for 16% of deaths in adult (\>4yo) Amur rat snakes** * Leading cause of death in Amur rat snakes \>8yo * 5 cases histopathology proven, cases 6-9 suspected but not submitted for histopathology * Premonitory clinical signs * Either died with no premonitory signs OR prominent dilatation of coelomic cavity in precloacal region, fecal impaction (4/5 cases), anorexia, coprostasis or egg stasis. ALL had thin body condition * Gross necropsy: marked thickening of colonic call cranial to cloaca, several tan to yellow firm masses in distal colonic wall (3/5 cases) * Histopathology: infiltrating, poorly circumscribed, and unencapsulated nests of epithelial cells * Mucus secretion in 3/5 cases * Anisokaryosis and anisocytosis in ALL cases, mitotic figures were scant * No histologic or gross evidence of metastasis * **Familial lineage in cases suggesting genetic predisposition or increased susceptibility of this lineage to infectious agent or environmental factor. No sex predilection.** * All confirmed cases descendants of one male and two females * **Numerous risk factors discussed in discussion that were specifically found in this case report** * **Familial/hereditary and causal association with Campylobacter-like bacteria in humans** * **Oncogenic viruses hypothetically causing neoplastic disorders in snakes** * **No reference to retroviral particles in previously reported cases of colonic adenocarcinomas in colubrids** **Take home**: Colonic adenocarcinoma accounted for 16% of Amur rat snake deaths with familial clustering suggesting a common etiologic factor

Answer 87

* Ferlavirus * Enveloped RNA virus * CS – respiratory noises, exudate, abnormal posture, head tremors, anorexia, and regurgitation * Pathologic findings – congestion/hemorrhage of the lungs, proliferative interstitial pulmonary disease – vacuolation of faveolar epithelial cells * Lesions also found in brain, spinal cord, liver, pancreas, salivary gland * Intracytoplasmic inclusion bodies are rarely observed * Diagnostics * Isolated from PCR – preferably with transtracheal wash, IHC can also be used on tissues * Epizootic * 17 snakes died from June – October 2013 after they were introduced – only one was euthanized, remaider died or were euthanized over the next three years * Eyelash vipers appeared to be more susceptible * Poor sensitivity of PCR resulted in changes * New Quarantine Protocol * Risk assessments before bringing in new snakes * PCR testing of tracheal washes & serology * Snakes with different temperature requirements are no longer quarantined in same facility – dedicated veterinary team member for care of snakes (not the herp department) * Any deaths during quarantine are fully investigated with ferlavirus testing Flach, E. J., Dagleish, M. P., Feltrer, Y., Gill, I. S., Marschang, R. E., Masters, N., ... & Tapley, B. (2018). Ferlavirus-related deaths in a collection of viperid snakes. *Journal of Zoo and Wildlife Medicine*, *49*(4), 983-995. **Abstract:** Between June and October 2013, 26 snakes of six viperid species kept in two adjoining rooms died (n = 16) or were euthanized on medical (1) or welfare grounds (9). Two were from the main zoo collection, but the other 24 had been imported and quarantined for a minimum of 6 mo. Four of those that died and the single snake euthanized on medical grounds showed minor signs of respiratory disease prior to death, and five were weak, lethargic, and/or poor feeders. Frequent postmortem findings among all snakes were poor body condition (18) and respiratory disease (13). Seventeen cases were examined histologically, and pneumonia, sometimes with air sacculitis and/or tracheitis, was present in 15 individuals. Lung samples from 24 snakes were ferlavirus polymerase chain reaction (PCR) positive, and one of the two snakes for which only liver was available was also positive. The negative liver sample was from a snake that died of sepsis following anesthesia for surgical removal of a spindle cell sarcoma. Correlation with antemortem PCR testing of glottal and cloacal swabs in five cases was poor (sensitivity = 40%). Immunohistochemistry (IHC) for ferlaviruses on the tissues of 13 PCR-positive cases showed positive labeling in 7 only. Tissues samples from 22 ferlavirus PCR-positive snakes were examined for Chlamydia species by PCR, and 9 were positive, although DNA sequencing only confirmed two of three tested as Chlamydia pneumoniae**. Immunohistochemistry for Chlamydia pneumoniae of seven cases (two Chlamydiales PCR positive, one of which was sequenced as C. pneumoniae, plus five negative) confirmed the Chlamydia PCR results. These two Chlamydiales PCR and IHC positive snakes were ferlavirus PCR positive, but IHC negative suggesting that, even though a ferlavirus was the predominant cause of the outbreak, in a few cases death may have been due to chlamydiosis with ferlavirus present, but not acting as the primary pathogen.**

Answer 88

* Ferlaviruses (FV, previously referred to as ophidian paramyxoviruses, OPMV) are enveloped viruses RNA * Determine seroprevalence and FV shedding in 150 samples from captive vipers in nine collections across Costa Rica * Hemagglutination inhibition (HI) assay was performed to determine the antibody titer against two Ferlavirus strains, Bush viper virus (BV) and Neotropical virus (NT), and reverse-transcriptase polymerase chain reaction (RT-PCR) and sequencing to determine virus secretion in cloacal swabs. * **FV seroprevalence were 26.6% for antibodies against BV, and 30% against NT; the majority of HI-positive samples were classified as low positives, with titers ranging from .10 to 80** * _Crotalus genus presented the highest number of positive samples in the HI assay per genera for both strains_ * quarantine period of at least 90 days and disinfection of cages could reduce the cases of FV infection * Recommended that an animal has a negative RT-PCR test for shedding before introduction * **Ferlavirus shedding can be detected in choana or cloacal swabs, and fluid recovered from tracheal washes, using RT-PCR or virus isolation in cell culture** * Study demonstrates serological evidence of viral exposure to FV in four genera of vipers, and the circulation of an FV-group A strain in one of the collections in Costa Rica Solis, C., Arguedas, R., Baldi, M., Piche, M., & Jimenez, C. (2017). Seroprevalence and molecular characterization of ferlavirus in captive vipers of Costa Rica. *Journal of Zoo and Wildlife Medicine*, *48*(2), 420-430.

Answer 89

Wojick, K. B., & McBride, M. P. (2018). Successful Treatment of Spectacle Avulsion in a Brazilian Rainbow Boa (Epicrates cenchria cenchria) by Using a Porcine Small Intestinal Submucosal Graft. *Journal of Herpetological Medicine and Surgery*, *28*(1-2), 23-28. Abstract A 5-yr-old, male Brazilian rainbow boa (Epicrates cenchria cenchria) presented with a partial spectacle avulsion that progressed to full spectacle avulsion following ecdysis. A porcine small intestinal submucosal graft was sutured over the cornea to protect the globe and allow the spectacle to regenerate. Treatment included topical antibiotic and lubricant ophthalmic medications. The porcine small intestinal submucosal graft was shed during ecdysis 30 days after placement, revealing peripheral regeneration of the spectacle with a 1- to 2-mm crust covering a presumed central defect. At the next ecdysis 39 days later, the spectacle had completely regenerated. Application of a porcine small intestinal submucosal graft in combination with topical antibiotic and lubricant ophthalmic medications for treatment of complete spectacle avulsion was successful in allowing spectacle regeneration and was well tolerated by the rainbow boa in this case. * Complete spectacle avulsion can lead to corneal desiccation, panophthalmitis, and ultimately loss of the eye * Porcine SIS is an acellular collagen rich matrix which provides a scaffold for tissue repair * Case report: brazilian rainbow boa had porcine SIS graft placed 13 days after initial partial avulsion and 2 days after complete spectacle avulsion OS * Porcine SIS was successfully used for complete spectacle regeneration within two ecdysis post graft placement * Prior to graft placement, globe became enopthalmic with corneal opacity -\> persisted post spectacle regeneration and suspected to be secondary to corneal rupture pre-graft * Regenerated spectacle opaque, suspected due to loss of organization of capillary network etc that allows for transparency in normal spectacle

Answer 90

Bogan Jr, J. E. (2019). An alternative technique for gastric sampling in snakes. *Journal of Herpetological Medicine and Surgery*, *29*(1), 13-16. ABSTRACT: Collecting gastric samples is often necessary when evaluating a snake exhibiting clinical signs of gastric cryptosporidiosis. Traditional techniques for obtaining these samples include gastric lavage and endoscopic or surgical biopsy. An alternative technique is described for collecting gastric samples in snakes using an equine uterine culture swab. * Gastric sampling important diagnostic for GI signs in snakes, primary ddx is cryptosporidiosis * Cryptosporidium serpentis causes marked hypertrophy of gastric mucosa, impeding digestion * Screening includes acid-fast staining, IFa staining, PCR assay (most sensitive) * Most sensitive collection method gastric biopsies 72hrs after feed * Need to use ethylene oxide gas for \>24h to kill Crypto, so not feasible with lots of snakes * In quarantine, gastric sample collection beneficial for screening asymptomatic snakes * Gastric lavage using flexible tubing typically performed for lots of animals, but can take a long time to pass a tube * Equine uterine culture swab, outer sheath lubricated into stomach; once there advanced inner sheath through to swab mucosa * Have collected samples from 266 asymptomatic snakes * Shorter than typical gastric lavage * Snake size limiting factor in sample collection (200g ok, large snakes limited by length) * Rigid swab allows for easier advancement into the stomach * Easier to use this to obtain samples from venomous snakes in acrylic tubes too * Does not replace endoscopy for diagnostic purposes

Answer 91

* Current diagnostic techniques → high rate of false neg * Low agreement - only 1 snake pos on both swab qPCR and histo findings * No agreement with fungal culture and qPCR (no positives with fungal culture) * Histo findings: marked ulcerative and crusting dermatitis, perivascular dermatitis, serocellular crusts, edema, and intralesional fungi that were branching, septate, and undulating with nonparallel cell walls * Characteristic dermal granulomas seen in advanced cutaneous cases of Ophidiomyces not seen in this study * Black Racers had the highest proportion of infected individuals * More positives April/May * Can’t diagnose based on histo alone as other fungi have similar morphology Take home: Ophidiomyces is a generalist fungi that has a high rate of false negative tests. It was more commonly seen in April/May testing months, and the authors recommend multiple modalities in order to increase sensitivity in testing. Long, R. B., Love, D., Seeley, K. E., Patel, S., Allender, M. C., Garner, M. M., & Ramer, J. (2019). Host factors and testing modality agreement associated with ophidiomyces infection in a free-ranging snake population in southeast ohio, usa. *Journal of Zoo and Wildlife Medicine*, *50*(2), 405-413.

Answer 92

* Boid Inclusion Body Disease * Caused by reptarenavirus * Majority of snakes are clinically normal * Clinical signs – neurologic disease, regurgitation, stomatitis, pneumonia, lymphoproliferative disorders * Approximately 20% will develop pneumonia * **Eosinophilic to amphophilic perinuclear inclusion bodies in pseudostratified columnar epithelium** * Reptile trachea – pseudostratified, columnar, & ciliated epithelium * Mucociliary clearance * Cilliary beating cells, periciliary airway surface liquid layer, mucous layer * **Newcastle interferes with mucus clearance from nasal mucosa in chickens** * **Mycoplasma causes loss of cilia and basal cell proliferation in tortoises** * Snakes euthanized, tracheas examined * Large variation, found in most species – significantly lower ciliary beat frequencies may be a reptile thing or a sick reptile thing as no healthy individuals were included **Take Home:** **Inclusion body disease does not appear to affect mucociliary clearance. However, reptiles appear to have significantly slower ciliary beat frequencies compared to mammals and birds.** Wyss, F., Schneiter, M., Hetzel, U., Pathologie, F. T. A., Keller, S., Frenz, M., ... & Hatt, J. M. (2018). Investigation of the tracheal mucociliary clearance in snakes with and without boid inclusion body disease and lung pathology. *Journal of zoo and wildlife medicine*, *49*(1), 223-226.

Answer 93

* Salmonella normal enteric flora in reptiles. ZOONOTIC. * All reptiles should be presumed shedders regardless of test results * Salmonella enterica ssp. arizonae (spp. IIIa) and Salmonella enterica ssp. Diarizonae (ssp. IIIb) commonly associated with reptiles * Can harbor more than one serotype * Rarely causes clinical disease in reptiles → thought to be opportunistic pathogen when it does * 3 most common tests for salmonella in reptiles: * Bacterial culture * High specificity and PPV, but low sensitivity and NPV * False neg caused by intermittent shedding and poor collection/storage/culture techniques * Polymerase chain reaction (PCR) * Enzyme-linked immunosorbent assay (ELISA) **Take-home points: cloacal samples just as good, potentially better, than fecal samples for Salmonella culture. Need at least 2 monthly consecutive cloacal samples or 3 monthly consecutive fecal samples to find 100% of carriers.** Buscaglia, N. A., Weinkle, T. K., McDonough, P. L., & Kollias, G. V. (2019). Comparison of Two Sampling Methods for Bacterial Culture of Salmonella enterica ssp. arizonae from Burmese Pythons (Python bivittatus). *Journal of Herpetological Medicine and Surgery*, *29*(1), 40-48.

Answer 94

JAVMA 2023 261(4) 536-543 **Retrospective assessment of general anesthesia-related challenges, morbidity, and death in snakes 139 cases (2000–2022)** Discussion - Before 2015, a premedication plan typically consisted of a single agent, rather than a combination of drugs, butorphanol being the most popular choice in snakes. - After 2015, the most popular preanesthetic plan included one in which alfaxalone was administered alone or in combination with other drugs—typically hydromorphone or midazolam - Alfaxalone has steadily risen in popularity in snakes. - Snakes with high ASA statuses, low BCS, and concurrent disease are more likely to develop complications while under anesthesia. - Therefore, clinicians are advised to perform a detailed preanesthesia physical examination and determine a BCS and ASA status prior to considering anesthesia. - Only 25% of cases used a recovery agent (ie reversals) - Of monitoring parameters, oxygen saturation levels were the least likely to be monitored - 25% of cases did not record a single vital parameter - 8 (of 139) cases were euthanized due to poor prognosis, and 4 (of 139) failed to recover. - All snakes that failed to recover had preexisting disease identified pre-, peri-, or postoperatively at necropsy.

Answer 95

JHMS 32.2 (2022) **Oral Fluralaner (Bravecto®) use in the Control of Mites in 20 Ball Pythons (Python regius)** Johnny Gobble Key Points: - Ophionyssus natricis: Snake mite -- Lifecycle is 3wk; requires 6-9 weeks of treatment to stop infestation -- C/S: prolonged soaking, small black specs seen in water and on scales - Fluralaner: Osoxazoline -- Antagonizes GABA, arthropod specific -- Metabolism expected to be long in snakes because of high protein binding - reptiles metabolize protein bound drugs slower than mammals -- Overdose in mammals: vomiting, dermatitis, neurological signs - Large chews were turned into a suspension by soaking → 40mg/kg administered to each animal - Unclear in paper, but it seems that 24h later there were no mites seen on the snakes; certainly 12 weeks later there were no mites seen. Take Home: Oral fluralaner appears to be able to successfully control mites in ball pythons.

Answer 96

JHMS 32.2 (2022) **Spontaneous Echo Contrast in an Asymptomatic McDowell's Carpet Python (Morelia spilota mcdowelli) with Suspected Restrictive Cardiomyopathy** Clément Bercker, Clémence Hurtel, Lionel Schilliger Key Points: - Presentation and treatment for rat-bite induced rostram abscess with Pseudomonas aeruginosa - Restrictive cardiomyopathy previously documented in this species and seen here, first time spontaneous echo contrast was seen with blood stasis (no thrombus seen) -- characterized by a swirling blood flow, caused by interactions between erythrocytes and plasmatic proteins under low shear stress conditions -- “Pre-thrombotic smoke” - indicative of blood stasis and predictive of thrombus formation -- associated with increased mortality in cats with cardiomyopathy - Snake was asymptomatic for severe cardiac disease - routine echocardiography is encouraged in normal appearing snakes Take Home: Severe restrictive cardiomyopathy with spontaneous echo contrast was seen in an asymptomatic McDowell’s carpet python, but is associated with thrombus formation in other species.

Answer 97

JHMS 32.2 (2022) **Cardiac Tamponade Following Cardiocentesis in a Ball Python (Python regius)** Jessica R. Comolli, Brittany McHale, Spencer Kehoe, Jörg Mayer Key Points: - Cardiocentesis generally thought to be a safe way to collect blood from snakes -- Previous studies in pythons showed minimal histological / clinical side effects even when multiple cardiocenteses performed. - This was a case report of a ball python that died shortly after cardiac venipuncture -- Snake was anesthetized and cardiocentesis performed by an experienced tech -- Swelling in area of heart seen just after cardiocentesis, followed quickly by cardiac arrest  -- Necropsy detemined case of death to be acute cardiac tamponade secondary to hemopericardium -- Snake had mild respiratory disease but no evidence of pre-existing cardiac diseaese Take home: Hemopericardium and fatal cardiac tamponade are rare potential side effects of cardiocentesis in snakes

Answer 98

JHMS 32.3 (2022). **Review of Chronic Ovoretention in Rattlesnakes (Crotalus and Sistrurus spp.) at a Single Zoological Institution** Sarrah Kaye, Marc Valitutto Key Points: - Retrospective study of ovoretention in 8 species of rattlesnake at a single institution. -- Diagnosed in 16% of mature female snakes during study period, and was the most common diagnosed cause of morbidity and mortality (case fatality rate was 50%). - Seasonality, parity, sperm exposure, clinical signs and severity of disease at presentation were variable (ranged from peracute death to more chronic illness). -- More proactive monitoring in apparently asymptomatic animals may help to catch cases earlier before they die acutely - Ultrasound more sensative than radiographs for diagnosis. - Medical management consisted of combinations of fluids, antibiotics, and oxytocin, but was rarely successful. -- Arginine vasotocin (AVT) is responsible for contractions during parturition in snakes and may have been more efficacious than oxytocin, but is not commercially available. -- Other studies in oviviparous snakes have demonstrated medical therapy is much less likely to be successful after 3 days due to eggs adhering to oviduct. - Surgery generally had good outcomes and some snakes successfully bred and had viable litters several years following surgery. - Co-morbidities included bacterial salpingitis and/or oophoritis (consequence vs cause of ovoretention?), uterine rupture (in an animal treated with oxytocin), sepsis, and disseminated mycobacteriosis. - In authors’ opinion, intervention should be pursued in snakes with clinical signs of disease or ova retained postpartum, or in subclinical animals that retain nondeveloping ova beyond 3-4 months. Takehome: Chronic ovoretention is a common problem in captive rattlesnakes and contributes significantly to morbidity and mortality. Surgery is more likely to be successful than medical management.

Answer 99

JHMS 32.4 (2022). **Cloacally Located Kidney Prolapsing in a Kingsnake Species (Lampropeltis spp.)** Jade Hardy, Ethan Biswell, Nicole Hardy, Curtis Eng Key Points: - Organ prolapses through the cloaca are a relatively common occurrence -- Treatment: reduction or resection -- Prolapse associated with: straining (intestinal disease), mating, neoplasia, urinary calculi, cystitis, metabolic bone disease, obesity, muscular weakness -- Distal GI tract, urinary bladder, phallus/hemipenes and oviduct are most common prolapsed organs - 8yo F Kingsnake with caudal coelomic swelling - multiple firm masses palpated -- Enema administered, snake passed a pedunculated mass -- Died 72h after procedure with no clinical signs - Necropsy: Mass confirmed as kidney with bacterial granulomas and gouty tophi -- Multifocal granulomas present in colon and oviducts - Suspect that an enteritis lead to breach of colonic wall and then spread to kidney and repro -- Cloacal tissue healed behind the kidney, trapping it in cloaca and causing fecal buildup cranial: No signs of acute rupture of the cloaca, ligation around pedunculated stalk was in the cloaca - Renal Dz: -- Bacterial nephritis caused by: Salmonella, Pseudomonas, Microsporidia, Spironucleus, Klossiella and Myxozoa -- Gout: dehydration most common cause, excessive dietary purines and nephrotoxic drugs - Bacterial Salpingitis: Pseudomonas and Salmonella most common causes

Answer 100

JHMS 32.4 (2022). **Evaluation of the Drug Combination Nitazoxanide, Azithromycin, and Rifabutin as a Treatment for Cryptosporidium serpentis Infection in Eastern Indigo Snakes (Drymarchon couperi)** James E. Bogan Jr, Michelle Hoffman, Mark A. Mitchell, …James F. X. Wellehan  Key Points: - Eastern indigo snakes are native to the SE US; populations are threatened due to habitat loss and fragmentation  - Ophidian gastric cryptosporidiosis caused by Cryptosporidium serpentis is a common parasitic disease in captive snakes  -- Associated with substantial morbidity and mortality  Take home: While it decreased shedding, the drug combination of nitazoxanide (20 mg/kg), azithromycin (10 mg/kg), and rifabutin (5 mg/kg) by mouth twice weekly for 6 weeks is not an effective treatment regime for Cryptosporidium serpentis in eastern indigo snakes

Answer 101

**INNATE IMMUNE FUNCTION IN LAKE ERIE WATERSNAKES (NERODIA SIPEDON INSULARUM) WITH OPHIDIOMYCOSIS** Ellen Haynes, Mark Merchant, Sarah Baker, Kristin Stanford, Matthew C. Allender Journal of Wildlife Diseases 58 (2), 279-289 Key Points: - Ophidiomycosis - caused by the fungus Ophidiomyces ophidiicola, all species of snake susceptible and disease has been assocaited with population declines  - Disease: typically skin lesions (few displaced or thickened scales, necrotic scales, larger crusts, or ulceration; if severe swelling/deformity), rarely systemic. Also see lethargy, poor body condition and difficulty with or increased rates of shed  - Infection severity might be linked to snake immune status (immunocompromised more severe), however not demonstrated in pygmy rattlesnakes previously  - innate immune response → primary defense against infection in reptiles, nonspecific and occurs quickly after exposure to a pathogen (nonspecific leukocyte responses, lysozymes, antimicrobial peptides, and complement) . Adaptive response → pathogen-specific, takes more time -- In humans enzyme chitotriosidase targets chitin in the cell walls of protozoan parasites, fungi, and nematodes as part of innate response (detected in alligators too) - Snakes appear to have lower levels of chitotriosidase than alligators Take Home:  There were no significant differences in innate immune function in Lake Erie water snakes with and without lesions due to Ophidiomyces ophidiicola at any severity level.

Answer 102

**REPEATED SAMPLING OF WILD INDIVIDUALS REVEALS OPHIDIOMYCES OPHIDIICOLA INFECTION DYNAMICS IN A PENNSYLVANIA SNAKE ASSEMBLAGE** Amanda L. J. Duffus, Daniel F. Hughes, Andrea Kautz, Steven J. R. Allain, Walter E. Meshaka Jr Journal of Wildlife Diseases 58 (2), 290-297 Key Points: - Looked for skin lesions and also swabbed for PCR. -- About half had skin lesions consistent with Oo. -- Only 2/34 positive on traditional PCR, versus 15/34 positive on qPCR -- Surprising finding - other studies have shown better agreement between methods -- Suggests that qPCR much more sensitive, and/or more likely to get false positives -- Fungal load by qPCR did not always correlate with severity of skin lesions - Two animals sampled at different time points, and had higher fungal loads by qPCR correlating with higher severity of skin lesions at certain time points -- Suggests that repeated sampling can help to understand disease dynamics - Previous studies have shown some snakes can clear clinical signs of Oo infection, but this does not necessarily equal clearing of infection. Takehome: qPCR is more sensitive than traditional PCR for detection of ophidiomyces ophidiicola. Clinical signs and fungal load can vary in individuals over time.

Answer 103

JWD 58.4 (2022). **SEASONAL AND INTERSPECIFIC VARIATION IN THE PREVALENCE OF OPHIDIOMYCES OPHIDIICOLA AND OPHIDIOMYCOSIS IN A COMMUNITY OF FREE-RANGING SNAKES**  Rachel M. Dillon; James E. Paterson; Pilar Manorome; … Christina M. Davy Takehome: * Eastern foxsnakes (Pantherophis vulpinus) had the highest prevalence of O. ophidiicola (24/84) and of lesions consistent with ophidiomycosis (34/84). * On other species (Nerodia sipedon, Storeria dekayi, Thamnophis sirtalis, and Thamnophis sauritus), we detected the pathogen on only 4/229 snakes and observed gross lesions consistent with ophidiomycosis on 24/229 snakes * Prevalence of ophidiomycosis is highest in eastern foxsnakes on emergence from brumation, consistent with other studies. * This study also found a higher prevalence in animals collected from marsh habitats compared to drier habitats, and in larger snakes compared to smaller.

Answer 104

JZWM 53.2 (2022) **THE EFFECT OF VARIED ENRICHMENT TYPES ON SNAKE BEHAVIOR** Sneha Krishnan, Eric Klaphake, Sangeeta Rao, Miranda J. Sadar Take Home: Offering enrichment to snakes may (non-statistically significant results) encourage desirable behaviors (exploration, interaction with environment) and decrease undesirable behaviors (interacting with glass). 

Answer 105

JZWM 53.3 (2022) **COMPLETE UNILATERAL MAXILLECTOMY IN A COHORT OF FIVE COLOMBIAN BOAS (BOA IMPERATOR)** Clément Paillusseau, Frédéric Gandar, Lionel Schilliger Key Points: - Snake skulls unique: absence of a mandibular symphysis, presence of a mobile quadrate bone and, in some species, a high degree of mobility of the maxillary bones allowing independent movement of toothed bones facilitating large prey ingestion;  Pleurodont teeth  . - Because the maxilla is attached to neighboring bones by soft tissues in pythonids and boids, postoperative healing can be maximized, as no osseous tissue resection is necessary - Using a lateral gingival approach, the maxillo–prefrontal, maxillary–palatine, and maxillo–ectopterygoid attachments were transected, and the maxillary bone removed - complete unilateral maxillectomy in boids does not substantially affect food intake when snakes were fed small, dead prey - Surgical dehiscence seen in one animal - risks = more friable gingiva in snakes, oral flora, mastication trauma (reduce with monofilament suture, continuous pattern, taper needle not cutting, fasting patient for period post-op to allow healing, antimicrobials - gram neg) - Nerve block for maxillectomy: trigeminal nerve (V) contributes to sensory and motor innervation of the head in snakes. It is divided into the ophthalmic (V1), maxillary (V2), mandibular (V3), and pterygoid (V4). Maxillary branch innervates maxilla - emerges from the anterior prootic foramen (block here is contraindicated due to risk of iatrogenic lesion), distal block at infraorbital foramen yields incomplete block of maxilla, therefore local infiltration/periosteal infiltration recommended  Take home: Unilateral maxillectomy may be viable alternative to medical management for osteomyelitis in boid snakes

Answer 106

Hepps Keeney CM, Cohen EB, Lewbart GA, Ozawa SM. **ULTRASONOGRAPHIC EVALUATION OF COELOMIC FLUID IN HEALTHY CORN SNAKES (PANTHEROPHIS GUTTATUS)**. J Zoo Wildl Med. 2023 Mar;54(1):65-72. Key Points: - Free coelomic fluid in snakes can be from pathology (cardiac dz, neoplasia, renal or hepatic failure, and trauma); small volume reported as a normal finding; however, no reports on what volume or appearance would be considered normal - R3 (region with the stomach, splenopancreas and portion of intestine) in corn snakes is most likely to contain coelomic fluid in a normal animal - Ceolomic fluid can be normal in healthy snakes and is transudative. If cells present - predominantly lypmphocytic. - Also a reference paper for POCUS in snakes

Answer 107

ZB 2023 42(1) 119-132 **Ejaculate characteristics over seasons in five species of lancehead pitvipers Bothrops spp** Key Points: - Gonadosomatic Index (GSI) in Brazilian lanceheads did not vary throughout the year, whereas it increased in the autumn for Common lanceheads, Jararacussu, and Whitetail lanceheads. On the other hand, GSI declines occurred at different seasons for these three species, taking place in spring for Jararacussu and Whitetail lanceheads, and in winter for Common lanceheads. - Sperm count: only Jararaca and Whitetail lancehead demonstrated seasonal differences with increases during winter and spring, respectively - Seasonal variations in GSI did not seem to markedly impact sperm production or quality Takeaway: Although all snakes used in the study were kept within similar protocols of temperature, food, and humidity, the data suggest they can still maintain their reproductive characteristics according to their biome of origin, even if they are born in captivity.

Answer 108

JZWM 53.3 (2022) **PARASITOLOGIC AND PATHOLOGIC STUDY OF FREE-RANGING SOUTH AMERICAN RATTLESNAKES (CROTALUS DURISSUS TERRIFICUS) IN BRAZIL** Frank August de Oliveira Toledo, … Renato Lima Santos Key Points: - Vast majority of lesions were in the gastrointestinal system and of these lesions the majority were associated with metazoan macroparasites  -- Majority = granulomatous gastritis caused by ascarids Ophidascaris sp. or Hexametra sp. -- Snakes become infected after ingesting vertebrate intermediate hosts which harbor the infective stages (third-stage larvae). Larvae migrate from intestine to coelomic cavity and lungs, where they develop further. Fourth larval stages are seen in the esophagus, stomach, and intestine. Inflammation caused by migration.  -- Other = mild to moderate granulomatous inflammatory process on the surface of the lung  - Other infectious lesions were protozoan ( Sarcocystis sp., Cryptosporidium sp., and Entamoeba sp. in intestines) or fungal (mainly skin and skeletal muscle) -- Crypto more often seen in stomach os snakes, here seen in intestines -- Sarco lesions usually mild in snakes, here more prominent  - Hemoparasites were seen in a quarter of snakes examined: Hepatozoon sp.and Trypanosoma sp