Ratites

Question 1

What birds are in the Order Struthioniformes?

Answer 1

Ratites

Question 2

Unique features of ratites

Answer 2

Flat keel, features lack barbules, no uropygial gland, illia form shield over the synsacrum

Question 3

Unique feature of the Emu trachea

Answer 3

Tracheal sac - Series of incomplete cartilage rings on anterior aspect covered by thin membrane for drumming noises during breeding season

Question 4

Anatomical feature in emus, rheas, cassowaries that ostriches lack

Answer 4

Gallbladder

Question 5

What spp has two functional ovaries that ovulate alternately

Answer 5

Kiwi; Also they make GIANT eggs - This is normal

Question 6

Anatomical differences between Tinamous and Ratites

Answer 6

Tinamous are flighted, have well-developed pectorals, highly pneumatized skeleton, elaborate ceca

Question 7

Unique anatomic features of the skeleton

Answer 7

No patellas; Emus, cassowaries, rheas tridactyl; Cassowaries sharp claw inner toe

Question 8

Number of toes - Ostrich, cassowaries, emus, rheas

Answer 8

Ostrich didactyl with nail on medial toe only; Others tridactyl with nail on all toes

Question 9

Unique feather anatomy of ratites

Answer 9

Barbules do not interlock (fluffy); No down feathers; Continuously molt

Question 10

Unique metabolic differences between Kiwi and others

Answer 10

Kiwis have a lower basal average temp

Question 11

Compare and contrast GI anatomy for ostrich, rea, cassowaries, emus

Answer 11

Ostrich and rheas have small glandular patch in PV with thick-walled ventriculus; Ostrich has voluminous colon and small ceca; PV in emus and cassowaries large and diffusely glandular with small ventrilucus that lacks a koilin layer; Rhea has enormous paired ceca; Strong rectal-coprodeal sphincter results in separate defecation and urination

Question 12

Describe what position eggs needs to be in for ostrich incubation

Answer 12

Vertical positioning during incubation is beneficial, turning of eggs is crucial

Question 13

Compare and contrast rhea and kiwi reproduction

Answer 13

Rheas polygamous with 1 male competing for several females, communal nests, parental care exclusively by males; Kiwis pair for life, largest egg-to-body ratio (20% female BW).

Question 14

Compare and contrast ostrich and cassowary environmental ideals

Answer 14

Ostriches prefer semi-arid and are adapted to hot and dry environments; Cassowaries prefer rain forests. All may swim; Ostrich males territorial during breeding season, harem groups recommended.

Question 15

Compare and contrast diets for ostrich, emus, cassowaries, kiwi

Answer 15

Ostrich and rhea exclusively vegetarian; Emus eat a lot of insects; Cassowaries largely frugivores; Kiwis inverts in wild but meat and fruit/carbs in captivity

Question 16

What anatomic feature of cassowaries make manual restraint dangerous

Answer 16

Daggerlike claw on limbs

Question 17

Describe preventive measures/considerations for preventing capture myopathy in ratites

Answer 17

Vit E/Se, fluid therapy and NSAIDS; fast 12-24h before and restrain water for 4 hrs; Ideal dart perpendicular to proximal thigh; Underdosing may result in overexertion during excitatory phase. Excessive running during excitatory phase, refractory to sedative effect of opioids; Apnea common during anesthesia; Lateral recumbency for prolonged periods = peroneal nerve paralysis/padding essential

Question 18

IM injection sites in Ratites

Answer 18

Epaxials, proximal leg muscles; Lack pectoral musculature

Question 19

Spirochete assoc with necrotizing typhlitis in young rhea

Answer 19

Serpulina hyodysenteriae

Question 20

Etiologic agents for GI infections common in chicks

Answer 20

E. coli, Salmonella, S. hyodysenteriae, avian influenza, coronavirus, rotavirus, Histomonas meleagridis, cryptosporidia, Macrorhabdus ornithogaster

Question 21

Why are kiwi thought to be more susceptible to fungal infections?

Answer 21

Lower body temp vs other bird spp

Question 22

Tropism of EEE virus for emus and rheas

Answer 22

Unique visceral tropism results in GI symptoms; DIFFERENT than other birds (neuro dz)

Question 23

Nematodes found in deep proventricular glands and under koilin layer in ostriches

Answer 23

Trichostrongylid nematodes (Libyostrongylus)

Question 24

Rheas - Nematode between the koilin layer and ventricular mucosa

Answer 24

Sicarius uncinipenis

Question 25

Fatal cerebral nematodiasis Chandlerella quiscalis in ratites - what is its reservoir and transmission

Answer 25

Songbirds reservoir, transmitted by Culicoides mosquitoes

Question 26

Identify 5 drug/food toxicities in ratites

Answer 26

Lindaine-containing antiparasitics, lincomycin, streptomycin, colistin abx, Se oversupplementation in chicks; parsley - photosensitivity; avocado - epicardial edema and myocardial degeneration;\ oak leaves in cassowary - enteritis and nephritis

Question 27

Causes of developmental angular limb deformities in ratites.

Answer 27

Imbalances in vit D3, Ca, P, Mn, Zn, Cu, Se, riboflavin deficiency, protein excess.

Question 28

Cause of rickets in ratite chicks (folding fractures, ALD, pliable long bones)

Answer 28

Hypophosphatemia

Question 29

Viral disease that causes cutaneous nodules in kiwis

Answer 29

Avian pox; eosinophilic intracytoplasmic inclusions

Question 30

Avian influenza virus clinical signs in ostriches and emus

Answer 30

OIE reportable; Ostriches - anorexia, depression, poor growth, biliverdinuria; Emus - Respiratory signs.

Question 31

Name 2 OIE reportable diseases affecting ratites

Answer 31

Avian influenza; Newcastle

Question 32

Viral disease with high mortality in emus, causes hemorrhages throughout small intestines. How does this disease differ in cassowaries?

Answer 32

Eastern equine encephalitis; NEURO dz in cassowaries (NOT GI LIKE EMUS)

Question 33

Protozoal disease that causes significant disease in kiwi

Answer 33

Intestinal and extraintestinal coccidia - E. kiwi (intestinal); E. parairii (colorectal polyps); E. mantelli (feces); E. apteryxii (renal)

Question 34

Ostrich louse

Answer 34

Struthiolipeurus struthionis

Question 35

Which digit is the largest digit of the ostrich foot? Is there a connection between the metatarsophalangial joint cavities of the 2 digits? Are there communications between metatarsophalangeal joints 3 and 4?

Answer 35

Radiographic Anatomy of the Metatarsophalangeal Joint and Digits of the Ostrich (Struthio camelus) Tehrani PR, Gilanpour H, Veshkini A. J Avian Med Surg. 2017 Sep;31(3):198-205. * D3 – 4 phalanges with 3 interphalangeal joints. * First IP joint between P1, P2. * Saddle-shaped, sagittal groove and ridge system helps limit medial and lateral movement. * Second IP joint between P3, P2. * Third IP joint between P4, P3. * D4 (smaller, outer toe) – 5 phalanges, 4 IP joints. * Arthrography of MTP joint: * Dorsal, plantar pouches. * Pouches around flexor tendons. * No connection between MTP joint cavities of the 2 digits.

Question 36

What was the most common issue affecting ratite neonates \< 1wk in a French zoo? What type of rearing was this associated with? What were the most common issues for chicks - ostriches, rheas, emus? What were the most common issues for juveniles - Ostrich, rhea, emu? Adults? What conditions had an increased incidence with male sex?

Answer 36

RETROSPECTIVE STUDY OF MORTALITY IN CAPTIVE STRUTHIONIFORMES IN A FRENCH ZOO (1974–2015) Benjamin Lamglait, D.M.V., M.Sc., Dipl. E.C.Z.M. (Z.H.M.) Journal of Zoo and Wildlife Medicine 49(4): 967–976, 2018 SURVIVAL RATES: Emus 59% \> rheas 31%\> ostriches 29% AGE: chicks 38% \> neonate & juvenile 22% \> adult 10% \> subadult 8% Emu chick death and adult death LESS prevalent. Common rhea juvenile death MORE prevalent NEONATE (\<1WK) MOST COMMON = Yolk sac infection 97% - E. coli the most common bacterium identified (57% of tested) 2nd = musculoskeletal (emus and rheas = trauma or stress myopathy; ostriches = trauma, crushed by parents) CHICKS (1WK – 1 MO) Ostriches: DIGESTIVE (impaction \> enteritis \> FB and gastric perf \> rectal prolapse) \> sepsis Rheas: DIGESTIVE (most bacterial enteritis, E. coli and Salmonella most common) Salmonella serovars typhimurium and enteritidis suggestive of environmental contamination Emus: musculoskeletal (most perosis, leg deformitiy 🡪 euth) \> sepsis JUVENILES (1-\<6MO) Ostriches: DIGESTIVE (gastric impaction \> enteritis \> FB and gastric perf \> rectal prolapse) and musculoskeletal (mostly perosis) Rheas: DIGESTIVE (Salmonella fibrinonecrotic enteritis) Emus: musculoskeletal (mostly perosis) Subadults (6MO – 3YR) Ostriches and emus: trauma from conspecifics Rheas: musculoskeletal (stress myopathy during introduction of new individual to enclosure) Adults (\>3YR) Ostriches: trauma (mostly evisceration) \> genitourinary deaths (mostly fatal peritonitis d/t salpingitis) Emus: ocular issues (palpebral \> conjunctival) \*mostly males that were nesting Rheas: Digestive and sepsis SEX: males more likely to be affected by trauma (ostriches) and ocular disorders (emus) when adult age REARING: 1/3 parent reared, 2/3 hand-reared More yolk sac infection when hand reared Conclusions: Majority of deaths in neonatal, chick, and juvenile age groups was digestive origin, yolk sac infection (especially hand reared chicks), and trauma.

Question 37

A recent paper described a new technique for candling thick shelled eggs, like those of the emu and rhea. What is this technique? How did it affect the development of normal incubation?

Answer 37

ZB 2023 42(2) 296-307 **A new candling procedure for thick and opaque eggs and its application to avian conservation** Key Points: - Overall, these results indicate that the fenestration process has little effect on the normal incubation and hatching process. - The results show this study was successful in achieving its aims of developing and testing a method to safely apply egg candling methods to thick and opaque eggs via candling, with embryonic development observed for viable eggs - We have also demonstrated that this technique facilitates the application of existing blood draw methods, which was proven by the successful extraction of DNA from drawn blood samples from emu eggs - The procedure developed allows sex determination and therefore the incubation to be discontinued for an undesired sex within an ethical timeframe

Question 38

A recent paper described cervical esophagectomy and anastomosis in an ostrich. What is the scientific name of the ostrich? Why was an R&A needed? How was this bird anesthetized for the procedure? What are some common complications with esophageal surgeries?

Answer 38

JAMS 2023 36(4):421-425 **Subtotal Cervical Esophagectomy and Anastomosis in an Ostrich (Struthio camelus domesticus)** Zafalon-Silva B, Costa PM, Schmidt VRQ, C Beck CA, Alievi MM Key Points: - Provided supportive care 48 hours pre-op to better stabilize the ostrich -- Supportive care included analgesia and antibiotic coverage -- An esophagostomy tube was placed distal to the fistula during hospitalization -- Maintained post-op for 15 days too - Sedation: 4 mg/kg midazolam IM -- Induced with midazolam 0.1 mg/kg IV + ketamine10 mg/kg IV -- Maintained with 1.5-2.5% isoflurane during surgery - Performed partial esophagectomy then resection with end-to-end anastomosis -- Complications in esophageal surgeries: -- Delay in closure, dehiscence, fistulae, and strictures -- A double-layer suture closure was used to achieve end-to-end anastomosis - The fistula was likely caused by the accidental ingestion of a foreign body -- Ostriches in captivity are not selective in their feed intake TLDR: Successful outcome for the treatment of a fistulated esophageal stricture in a captive ostrich