Ruminants Flashcards

Question

Displaced Abomasum

Answer 1

Classic case: Multiparous dairy cow within 30 d of calving Partial anorexia and gradual weight loss Scant stool with different consistency from herdmates "Popped" or "sprung" rib cage: ribs pulled outward High-pitched tympanic or musical "ping" over ribs Ping on line betw L elbow & L tuber coxae (hip) for left DA (LDA) Ping on R for right DA (RDA) or right-torsed abomasum (RTA) If RTA: tachycardia, papple shape (pear on L, apple on R), colic, dehydration Dx: Ping on exam is usually diagnostic Rectal palpation: may palpate convex muscular organ in right abdominal quadrant for RDA/ RTA Expect hypochloremic metabolic alkalosis-twisted abomasum sequesters acid (HCl); possible acidosis if progressed to circulatory failure Liptak test: Insert 4.5-inch spinal needle transabdominally just ventral to ping & aspirate Acidic fluid = abomasal fluid Rx: Medical: Roll and toggle Blind stitch Supportive care: calcium, transfaunation, gastric stimulants Surgical: Abomasopexy Omentopexy Pearls: Prognosis excellent for life and return to productivity LDAs NOT emergencies vs. RDA/RTAs ARE emergencies Intervene in herd if prevalence of DAs is over 1% Good pre-partum feeding practices that maintain abomasal motility prevent most DAs

Answer 2

Classic case: Enzootic calf pneumonia: Thin, weaned calf with good appetite Tachypnea, cough Lung auscultation: crackles and wheezes, harsh sounds, no cranioventral sounds Shipping fever: Any age cow recently shipped or stressed Tachypnea, soft cough, sepsis Lung auscultation: crackles and wheezes, harsh sounds, no cranioventral sounds Dx: Etiology: Multifactorial - stress, +/- viral infection, and one or more of the following are commonly isolated... Enzootic pneumonia: Often Pastuerella multocida type A, but may be Mannheimia haemolytica, or Mycoplasma bovis Shipping fever: Most often M. haemolytica, but also may involve P. multocida, or Histophilus somni Tracheal aspirate, pharyngeal swab: culture, cytology Imaging: ultrasound & radiographs of thorax Pleurocentesis Rx: Appropriate, legal use of antibiotics Anti-inflammatories Pearls: Most calves recover but delayed time to maturity Worse prognosis if concurrent bovine virus diarrhea (BVD) infection Vaccinate against BVD, clostridial diseases, parainfluenza 3 virus, +/- P. multocida

Answer 3

Classic case: Vaginal prolapse: Mature cows with enlarged abdomen (fat, fetus, GI) Last trimester Grading system: Grade I: Intermittent prolapse, especially when recumbent Grade II: Continuous prolapse Grade III: Continuous prolapse of vagina, bladder, and cervix Grade IV: Grade II or III with tissue damage by trauma, infection, or necrosis Uterine prolapse: Within hours of parturition Risk factors: Multiparous cattle First-calf beef heifers Dystocia Retained membranes Hypocalcemia Atony Dx: Vaginal prolapse: May see cervix and inflamed mucosa Uterine prolapse: See cotyledons +/- retained placenta Rx: Vaginal prolapse: Epidural Lubricant Replacement Retain with Buhner suture (a deeply buried circumferential suture placed around the vestibule to provide support at the point at the initial eversion of the vaginal wall Salvage procedure is an option Uterine prolapse: Address shock Epidural Cleanse uterus Glycerol Lubricant Replacement: If recumbent, put cow in sternal recumbency with hindquarters elevated and pelvic limbs extended backward (like a frog) Helps you push the uterus "downhill" Repair by pushing uterine tip up and in, working between bouts of straining Once uterus is in normal position: Infuse warm, sterile saline solution to ensure complete replacement of the tip of the uterine horn without trauma Oxytocin plus IV calcium indicated in most cases to increase uterine tone Caslick sutures and other vulvar closures are NOT useful, because uterine prolapse begins at apex of uterine horn, NOT at vulva Pearls: Vaginal prolapse: There may be a genetic component Urethra may be occluded causing urinary bladder rupture Uterine prolapse: Prognosis is good to excellent for mature heifers, but poor for first-calf heifers Recurrence is rare if properly replaced

Answer 4

Classic case: Variable Subclinical (especially Staphylococcus aureus, coagulase-negative Staphylococcus spp., Streptococcus agalactiae) Acute (especially Streptococcus dysgalactiae, coliform): Systemic illness: fever, anorexia, tachycardia, diarrhea, depression, toxemia, serous to serosanguinous milk Chronic: Hot, firm udder, erythema, edema, pain, abnormal milk with flakes, fibrin, or blood Dx: Etiologies: Staphylococcus aureus (contagious), coagulase-negative Staphylococcus spp. (opportunistic) Streptococcus agalactiae (contagious) Streptococcus uberis (environmental, +/- contagious) Streptococcus dysgalactiae (environmental, +/- contagious) Trueperella pyogenes (contagious) Mycoplasma spp. or M. bovis (contagious) Listeria monocytogenes Coliforms (E. coli, Klebsiella, Enterobacter, Proteus, Serratia, Citrobacter) (environmental) Physical exam Cytology Culture (normal milk is sterile) California mastitis test (CMT) Measure somatic cell counts (SCCs) on individual cow or bulk milk Uses detergent to lyse SCCs Add equal volumes of milk and reagent and observe amount of gel formation CMT primarily used to detect or rule out SUB-clinical mastitis Watch a short video of how to do a CMT Regulatory authorities grade milk by SCCs SCCs are normally 75% white blood cells (WBCs) and 25% epithelial cells WBCs increase with mastitis Normal cow has less than 100,000-200,000 SCC/ml Normal parameters for bulk milk: Less than 750,000 SCC/ml Less than 10 coliforms/ml Less than 100,000 bacteria/ml Rx: Antibiotics: Systemic Intramammary infusion Frequent milking NSAIDs Dry cow therapy +/- Oxytocin to increase udder drainage Prevention: Decrease stress and environmental contamination Post-milking teat dipping/spraying Pre-milking teat dipping/spraying Dry cow therapy: Infuse all quarters at drying off Culling/segregation Proper milking machine management and testing Vaccines: Adjuncts only (for S. aureus, some Streptococcus spp.) Pearls: Predominant immunoglobulin in milk is IgG1 Neutrophils are most important defense in mammary gland Trueperella pyogenes mastitis ("summer mastitis") may be associated with sheep head fly Leptospira mastitis is called "milk drop syndrome" or "flabby bag" mastitis because the rapid drop in milk production results in a flaccid udder Cattle bedding is the usual the source of environmental bacteria, but several other sources may be involved (e.g., flies, intramammary infusions, ponds) Acute mastitis associated with high mortality vs. chronic which has low mortality

Answer 5

Classic case: More often dairy cows than beef cows Fetal membranes that have not been expelled for greater than 12 h are considered retained Protruding membranes hanging from vulva Malodorous discharge Delayed return to estrus +/- Toxemia Risk factors: Dystocia Abortion Twins Hypocalcemia Increased environmental temperatures Older cows Premature birth Induction of parturition Placentitis History of retained fetal membranes May increase risk of: Mastitis Metritis Ketosis Displaced abomasum Tetanus Dx: Membranes protruding from vulva No history of expelling membranes Rx: DO NOT pull Trim what is visible Cows expel in 3-11 d regardless of treatment (even no treatment) Systemic antibiotics if systemic illness NOT proven to help: Intrauterine antibiotics, PGF2α, oxytocin, estradiol, calcium Vitamin E/selenium supplementation may help to prevent in deficient herds Good dry cow management essential to prevent retained fetal membranes Pearls: Usually not harmful to the cow but can be repulsive to milkers and handlers Prognosis is good to excellent

Answer 6

Classic case: Second biggest reproductive problem after failure to detect estrus Occurs 3 d to 2 wks postpartum Decreased conception rates Shortened estrous cycle Purulent vaginal discharge May be subclinical Contributing factors: Over-conditioning Unclean calving environment Assisted calving, dystocia Retained placenta Unnecessary post-partum infusions Inaccurate heat detection (resulting in too much artificial insemination (AI)) Presence of Trueperella pyogenes or Ureaplasma Dx: Etiologies: Usually nonspecific infection Most often T. pyogenes (sometimes in association with Fusobacterium necrophorum) Other gram-negative anaerobes Campylobacter fetus venerealis or C. fetus fetus +/- Brucella abortus +/- Tritrichomonas foetus Leptospirosis Rectal exam: Large, fluid-filled uterus Endometrial cytology and culture +/- Ultrasonography Rx: PGF2α to lyse persistent corpus luteum If septic: Systemic antibiotics, NSAIDs, IV fluids DO NOT use uterine infusions or lavage Good dry cow management essential to prevent endometritis Pearls: Normal uterine involution gets rid of bacteria in most cows by 2 mos post-calving Cows more resistant to endometritis during estrus

Answer 7

Classic case: Follicular cysts: Nymphomania Short inter-estrus intervals Extended calving interval Increased heat behavior Mucoid vaginal discharge Luteal cysts: Anestrous behavior Dx: Rectal exam (cannot distinguish between follicular and luteal) Follicular cysts: Ultrasonography Thin-walled, less than 3 mm More than 25 mm in diameter Often multiple cysts Abscence of corpus luteum Low serum progesterone concentration Persist more than 10 d Luteal cysts: Ultrasonography Thick-walled, more than 3 mm More than 25 mm in diameter Trabeculae Usually a single cyst High serum progesterone concentration (luteal cysts secrete progesterone) Rx: Follicular cysts: GnRH; encourages ovulation Luteinizing hormone (LH)-type treatment Manual rupture per rectum may cause ovarian trauma and hemorrhage Luteal cysts: PGF2α; encourages luteal lysis Treatment will allow estrus in 3-5 d Do not rupture manually Pearls: Follicular cysts: Nymphomania is due to increased estradiol and decreased progesterone May have a genetic component GnRH causes release of LH from anterior pituitary

Answer 8

Classic case: Most common in high-producing dairy cows, cows on their 3rd or more lactation, Jersey cows, multiparous mature dairy or beef cows Occurs within 72 h post-parturition Associated with rapid-onset milk production 3 stages: I (mild) Ambulatory, weak, ataxic, or down with normal head posture Hypersensitive, excitable, restless, aggressive Fine muscle tremors, starting in flanks and triceps, ear twitching, head bobbing Bellowing II (moderate) Sternal recumbency Obtunded Cool extremities, low temperature Anorexic Increased heart rate and decreased heart sounds with weak pulses Smooth muscle paralysis which can lead to bloat, failure to defecate, loss of anal sphincter tone, inability to urinate (distended bladder on rectal palpaption) Neck in "S-curve" III (severe) Comatose Opisthonus Muscles flaccid Increased heart rate with no pulses Death can occur within hours if no intervention Dx: History and physcial exam: Weak cow that recently calved or is about to calve Hypocalcemia: (normals vary betw. labs) Total blood calcium Ionized blood calcium RULE OUT SEPSIS ON ANY DOWN COW WHO CALVED RECENTLY CHECK UTERUS (for possible dead twin) CHECK UDDER QUARTERS/MILK (for possible septic mastitis) Hyperglycemia can occur because low extracellular calcium inhibits insulin secretion Rx: Calcium is cardiotoxic! Intravenous calcium, generally: Auscult heart and palpate pulses during infusion Stop and wait if bradycardic, arrhythmic, pulse weakens, or cow begins to pant Signs of improvement are decreased heart rate, strong pulses, eructation, able to rise, urination/defecation Re-treat if not standing within 4-8 h Float cow in a water tank if refractory Correct lateral recumbency as cow may regurgitate and aspirate Prevention: Low calcium diet during dry period Use dietary cation difference (DCAD) during late-dry and early-milking period to decrease blood pH Feed vitamin D3 late-dry Administer PTH just before parturition Avoid diets high in potassium and low in anionic ions Pearls: 75% of cows stand up within 2 h of treatment and 30% of those relapse The practice of completely milking them out to increase calcium reabsorption from mammary gland leads to mastitis and is no longer recommended Prognosis is good to excellent if no concurrent disorders

Answer 9

Classic case: Variable Normal stages of parturition: Stage 1: Beginning: Uterine contractions and cervical dilation Completion: Amnion and part of the fetus enter the vagina, "water breaking" Usually lasts 1-4 h Stage 2: Beginning: Abdominal contractions Completion: Fetal expulsion Usually lasts 1-4 h; in mature cows should last less than 3 h Stage 3: Fetal membranes expelled Beginning of uterine involution Usually occurs within 12 h after parturition Dystocia: Presentation appears abnormal Cow looks fatigued Calf looks compromised In stage 1 for greater than 6 h In stage 2, amniotic sac visible for 2 h and cow not trying In stage 2 and cow trying for more than 30 min without progress In stage 2 and cow not trying for over 20 min after initial progress Heifers should deliver within 60-90 min of seeing calf's feet Cows should deliver within 30-60 min of seeing calf's feet Risk factors: Weight loss in late pregnancy Pelvic canal width Male calves Cold weather leads to longer gestation and higher birth weight Dx: Various etiologies: Fetopelvic dysproportion: Dam factors: Genetics, age, parity, nutrition Calf factors: Size (genetics and environment), gender, gestational length, breed, genotype Cause of 30% of all dystocias and 50-90% of beef cow dystocias Malpresentation Over-conditioned dam Uterine torsion Milk fever Uterine inertia: Primary: Due to hypocalcemia, uterine overstretching, abnormal uterus, hormone levels, contractions Secondary: Exhaustion after prolonged attempts to expel fetus Rx: Vaginal assistance: Mutation: Return of fetus to normal presentation, position and posture Click here to see a video demonstration of correcting a calf with leg back Click here to see a video demonstration of correcting a calf with head back Click here to see a video demonstration of correcting a calf with breech presentation Traction C-section: Standing or under general anesthesia Fetotomy Prevention: If small pelvic canal width, either cull or breed to small bull and watch calving closely Choose sires that have low-weight calves by using Expected Progeny Differences calculation for determining calf size Pearls: Problems with calf after dystocia: Stillbirth Metabolic and respiratory acidosis Cool calf Failure of passive transfer

Answer 10

Classic case: May occur early-, mid-, or late-term (1st, 2nd, or 3rd trimester) Cow no longer pregnant Finding a dead, mummified, or partially autolyzed fetus Dx: Etiologies: Noninfectious: Genetic malformation (maternal or fetal), fever, stress, twin pregnancy, toxins (Ponderosa pine needles, locoweed, broomweed, nitrates, prostaglandins - toxins usually involve multiple animals) Neospora caninum : Usually late-term abortion in multiple animals Bovine viral diarrhea (BVD): Usually early abortion, but can be anytime; usually multiple animals Infectious bovine rhinotracheitis (IBR): Usually early- or mid-term abortion Leptospirosis: Usually late-term abortion in multiple animals Brucellosis: Usually late-term abortion Fungal placentitis Trueperella pyogenes Tritrichomonas foetus : Usually early abortion Campylobacter fetus venerealis : Usually early abortion in multiple animals Listeria monocytogenes : Usually late-term abortion, but can be anytime; usually involves only a single cow Ureaplasma diversum : Usually late-term abortion Epizootic bovine abortion (foothill abortion): Usually mid-term abortion Bluetongue Salmonella spp.: Usually involves multiple animals Definitive diagnosis difficult (only 30% of cases) due to fetal autolysis, disappearance of toxins, self-correction of physical causes, and because abortion often occurs long after infection Rx: Prevention: Vaccinate dams against: Leptospirosis, IBR, BVD, brucellosis, Campylobacter fetus Test bulls for trichomoniasis Check feed for nitrates Keep dogs off of pasture to prevent Neospora caninum Wait until 3rd trimester before allowing dams on foothill agent-infected pastures Pearls: Normal abortion rate is 1%; investigate if 3-5% Brucellosis and trichomoniasis are REPORTABLE The next blarticle will cover bovine abortion in more detail

Answer 11

Classic case: Early embryonic death Prolonged luteal phases Irregular estrous cycles Repeated breeding Unusually long calving intervals Carriers may have no clinical signs Endometritis Dx: Testing cows is usually more reliable than testing bulls Etiology: Campylobacter fetus venerealis or C. fetus fetus Culture: Difficult Microaerophilic or anaerobic Bacteria is labile (innoculate Clark's media to improve survival of bacteria for culture) Placental samples may be contaminated with fecal Camplyobacter spp. Vaginal mucus agglutination test (VMAT) (sample at least 10 cows) ELISA on vaginal mucus Best way to diagnose is to test-breed heifers and check for infection Sheath wash from bulls: Fluorescent antibody and/or culture Rx: Vaccination once diagnosed: Helps eliminate bacteria Improves fertility Bulls are given double the dose as cows Bulls may be treated with streptomycin systemically and topically to penis; cows usually not practical to treat Prevention: Artificial insemination Purchase only very young bulls Pearls: Transmitted by contaminated semen or, rarely, fomites Some animals may have transient infection while others may become chronic carriers Can spread rapidly within a herd

Answer 12

Classic case: Embryonic or early fetal death most common Repeated breeding Increase in number of nonpregnant normal cows and late-bred cows +/- Pyometra +/- Later fetal death or abortion Dx: Bulls are usually tested, rather than cows, since they are carriers Etiology: Tritrichomonas foetus, a pyriform or pleomorphic protozoan Preputial douche or aspirate: Darkfield contrast microscopy Culture with Diamond medium for over 48 h More than 90% cases are cultured successfully Rx: Imidazoles: Treating bulls with pronidazole most effective, but can cause sterile abscess at injection site Semen can be treated with dimetridazole Control: Test and cull positive bulls Cull all bulls and replace with virgin bulls Cows with calves and virgin heifers are presumed to be uninfected Vaccination may improve breeding in heifers, but not in bulls Pearls: Transmitted between cows by bulls Usually self-limiting in cows Reinfection of bulls after treatment is possible as is treatment resistance REPORTABLE in many states

Ruminants Flashcards

(36 cards)