L1: Sheep And Goat Diseases (Reuss) Flashcards
Which are most likely to show CS from Blue tongue: sheep or goats?
Sheep
Contagious ecthyma
- aka orf, soremouth
- caused by parapox virus
- crusting lesions of mucocutaneous jxs (mouth, nose, feet, genitalia, udders)
- zooonotic!
- usually self-limiting
Contagious ecthyma transmission, dx, tx, prevent
Trans: direct contact, environmental, gains entry through abrasions
Incubation period: 4 days - 2 wks
Dx: histopath, virus isolation, fluorescent Ab
Tx: supportive
Prevent: biosecurity, live virulent vaccine
Azalea toxicity
(Also laurels, rhododendron)
- entire plant toxic
- must eat >0.1% of BW in foliage
- Andromedotoxin alters Na conduction –> prolonged nerve depolarization –> vomiting, brady
- Tx: charcoal, atropine, fluids, +/- rumenotomy to empty rumen contents if severe, +/- abx for aspiration pneumonia
Dff and ages for diarrhea in lambs and kids**
- E. Coli: 1-4 days
- Rotavirus: 2 days-16 wks
- Cryptosporidium parvum: 5-10 days
- Giardia: first few weeks
- Salmonella: any age
Diseases of the oral cavity
- Actinobacillus ligneiressi (Woody tongue)
- Blue tongue
- Malignant catarrhal fever (sheep infect cattle*)
- Vesicular stomatitis
Clostridium perfringens. Type C
- produces alpha and beta toxin that is degraded by trypsin
- seen in neonates less than 10 days old (because they don’t have trypsin yet)
- can be seen in slightly older animals if they have concurrent rotavirus
- causes neonatal hemorrhagic enterotoxemia, necrotic enteritis, acute death
Clostridium perfringens Type D
- normal GIT inhabitant
- produces epsilon and alpha toxin that is ACTIVATED by trypsin
- mature animals affected
- causes enterotoxemia, overeating dz, pulpy kidney
Typical hx and pathophysiology of C. Perfringens enterotoxemia
- well fed rapidly growing lambs acutely deteriorate
- pathophys: heavy grain feedings or very rich pasture; Type D toxin elaborates and is activated, epsilon toxin increases intestinal permeability –> edema of lungs, kidney, brain
CS of enterotoxemia
Sheep: lethargy, neuro signs, death, minimal diarrhea
Goats:
- peracute (young goats): diarrhea, severe colic, fever, death
- acute (mature goats): diarrhea, colic, dehydration
- chronic
Dx of enterotoxemia
- dehydration, azotemia, leukocytosis
- hyperglycemia, glucosuria**
- enterocolitis, pulpy kidney, hydropericardium, encephalomalacia
- culture not helpful (found in n animals)
- ELISA or PCR to isolate epsilon toxin
Tx of Enterotoxemia
- IV fluids, bicarb, electrolytes
- type C and D antitoxin (backordered)
- NSAIDs
- Abx (penicillin, oxytet, sulfas)
- avoid high grain feedings
- peracute dz has guarded prognosis
Vaccination for enterotoxemia
- better in sheep than goats
- CD-T vaccine provides best protection against perfringens compared to other multi-valent vaccines
- give initial vax then booster 3-6 wks later
- booster goats q3-4 months, sheep q6-12 months
- booster dams 2-3 wks before parturition
- start kids at 4-6 wks
Coccidiosis cause
- caused by host specific Eimeria spp
- sporulates in high moisture, moderate temps
- oocysts survive for years
CS of coccidiosis
- diarrhea +/- blood, mucus
- Anorexia, dehydration, weakness, rough haircoat, weight loss, rectal prolapse, death
- scarring of mucosa –> chronic poor growth
Coccidiosis common in what age small ruminants?
1-4 months, >7 years
- stressed animals
- dz of confinement
Dx/Tx/prevention of coccidiosis
Dx: direct smear, fecal flotation
Tx: coccidiostats (sulfadimethoxine, amprolium); resistance a problem
Prevent: monensin, lasolocid, amprolium, decoquinate
Most significant clinical dz of SR?
Haemonchus contortus (barberpole worm)
- comprises 75-100% of total fecal nematode eggs
- sucks 1 drop of blood/day
- produces 1,000-6,000 eggs/day
PPP of haemonchus contortus?
4-5 weeks
- can survive 180d on grass
- takes 3 weeks from ingestion to eggs being released in feces
Haemonchus lifecycle
1) L3 ingested by goat on grass
2) molts to L4 and matures to adult in abomasum
3) 3 weeks later: eggs in feces
- can have arrested development in poor conditions
- can live 4-6 months inside host
Conditions haemonchus likes?
Warm, moist
CS of haemonchus
- poor growth/production
- weight loss
- diarrhea
- anemia
- hypoproteinemia (edema, bottlejaw, ascites)
- death
Dx of haemonchus
- McMaster’s Quantitative Fecal Egg Count (>750 epg clinically relevant)
- larval culture
90% of farms resistant to which dewormers
Albendazole
Ivermectin
> 50% farms resistant to
Moxidectin (48% resistant to albendazole and ivermectin also)
Refugia
Portion of parasite population not exposed to a drug
- most important factor in how quickly resistance develops
- supplied by stages not affected by tx, animals not treated, and free-living stages
DrenchRite test
Evaluates resistance to all classes of dewormers
Anthelmintic resistance measured by:
- CS in treated animals
- Fecal egg count reduction test
- DrenchRite test
FAMACHA: who and when to check
- weekly during wet periods
- q2-3 wks early during season
- q4-6 wks when cool, dry season
- check every goat then do random sampling
Benefits of FAMACHA
- reduces tx and drug costs
- increases labor costs (downside)
- insures adequate refugia
- scores heritable
Smart drenching guidelines
- administer proper dose
- administer drug properly (fast for 12-24 hrs beforehand, use drenching gun, put on dry lot for 3 days post-tx)
- utilize environmental management (pasture management, mixed livestock species grazing)
- biosecurity
Alternative therapies for Haemonchus
- Copper oxide wire particles (very effective in sheep, however caution for copper toxicity)
- condensed tannin-containing forages (Sericea lespedeza; tannins bind to and damage cuticle)
- nematode-trapping fungi (parasitizes the worm larvae in feces; must feed daily)
- genetic management (cull high FAMACHAs, monitor FECs)
- nutrition (protein supplementation)
- diatomaceous earth (doesn’t work!)
- herbal
- vaccination
Transfusion triggers
- tachycardia, recumbency
- PCV
Transfusion equation
(Desired PCV-patient PCV) x (0.08x BW). /donor PCV
Cause of caseous lymphadenitis
Corynebacterium pseudotuberculosis
(G+ intracellular coccobacillus)
- produces exotoxin phospholipase**
- survives in dark damp manure
- shed for 37 days after rupture
- ovine/caprine biotype
CS of caseous lymphadenitis
- abscesses in skin and LN: green/cream non-fetid pasty pus
- visceral dissemination (sheep > goats) to lung, abdomen, CNS, mammary gland
Dx/Tx/Prevent of Caseous Lymphadenitis
Dx: serology (low specificity), culture
Tx: isolate, lance and flush, sx removal, or closed system lavage, with systemic abx
Prevent: cull, disinfect shearing equipment, vaccinate with bacterin toxin (decreases severity only)
Pathophys. Of pregnancy toxemia
Insufficient energy density + decreased rumen capacity –> Negative energy balance during late pregnancy most commonly.
- The liver increases gluconeogenesis to facilitate glucose availability to the fetuses.
- Increased fat mobilization can –> hepatic lipidosis
- inadequate nutritional intake –> less responsive to insulin
- difficulty clearing ketone bodies in the liver –> ketosis
Risk factors for preg tox
- decline in nutritional plane
- multiple fetuses
- overconditioned in early gestation
- concurrent dz
CS of preg tox
- late gestation
- anorexia
- depression, separation from herd
- tremors, star-gazing, ataxia, recumbency
- odor of ketones
Dx of preg tox
- ketonuria, proteinuria
- ketonemia (beta-hydroxybutyrate, which isn’t picked up on test strip)
- metabolic acidosis
- hypoCa, hypoK, hypoglycemia
- azotemia
- inc. liver enzymes
Tx of preg tox.
- decide to save dam or feti
- immediate C-section to save dam or induce labor to save feti
- medical management risky for everyone
Normal rumen chloride in cows:***
Less than 32
How does Caseous lymphadenitis spread?
- Entry: intact or broken skin, inhalation, mm, fomites, direct transmission
- spreads via lymphatics to LN, internal organs
- incubation period = 3 wks to 6 mos.
Tx of preg. Tox.
- restore energy balance by feeding energy dense feed, propylene glycol, transfaunation, IV glucose, insulin, correct Ca/K
- remove feti
Prevention of preg tox
- feed based on number of fetuses
- ionophores, niacin (helps with feed efficiency)
- decrease stress
- shear sheep in last trimester (induce shivering and insulin sensitivity)
- monitor serum BHB
Pathophys. Of hepatic lipidosis
- increased FFA mobilization, TG production overwhelms ability to package into VLDLs –> TG deposited in liver
- insulin resistance perpetuates (insulin normally decreases fat mobilization)
- sequela to preg tox
Dx of hepatic lipidosis
- liver enzymes (unreliable), AST >100
- NEFAs >1000 if lactating, >350 if peripartum
- ketonuria
- U/S
- liver biopsy (will float)
Tx of hepatic lipidosis
Corticosteroids (short term)
Vit. E, selenium, glucagon
Causes of pseudopregnancy
- hydrometra, mucometra
- prolonged luteal phase
Pseudopregnancy common in what animals?
Adult dairy goats (3-5%)
CS of pseudopregnancy
-udder development, bloody vaginal discharge, anestrus, behavioral signs
Dx/tx of pseudopregnancy
Dx: U/S, progesterone lvls increased
Tx: PGF2-alpha
Causes of inappropriate lactation
- pseudopregnancy
- self suckling
- estrogenic compounds
Dx of mastitis
- PE
- California mastitis test
- culture
Common bacterial causes of mastitis
- coliforms
- listeria
- M. Haemolytica (sheep)
- Staph aureus
- Staph epidermidis, intermedius, caprae, hyicus
- Pseudomonas
- Strep agalactiae, zooepidemicus, etc.
Tx of mastitis
Intramammary cephapirin, ceftiofur, pirlimycin, penicillin (caution with drug withdrawals*)
Systemically: frequent stripping, flunixin meglumine
Gangrenous mastitis
Aka “bluebag”
- caused by staph aureus, coliforms
- tx: systemic abx, supportive care, mastectomy, teat amputation, chemical sterilization
Common multisystemic diseases of SR
Mycoplasma
Chlamydia
Ovine Progressive Pneumonia (OPP)
Caprine Arthritis Encephalitis (CAE)
CS of mycoplasma
- mastitis: green/yellow with granular sediment
- pneumonia
- neutrophilic fibrinous polyarthritis
- KCS
- peritonitis, pericarditis
Dx/Tx/Prevent of mycoplasma
Dx: PCR, serology (difficult to grow in culture)
Tx: tulathromycin, florfenicol, oxytetracycline
Prevent: pasteurize colostrum, milk, cull carriers
- may continue to be carriers
- 80-90% morbidity and mortality
Chlamydia common in what population?
Feedlot lambs
-caused by Chlamydophila pecorum
CS of chlamydia
- fever
- pneumonia
- polyarthritis
- KCS
- abortion
-dz course 10-14 days
Dx/Tx of Chlamydia
Dx: PCR, inclusion bodies, fluorescent Ab tests, CF titers
Tx: oxytetracycline, erythromycin, tylosin, isolation
Ovine Progressive Pneumonia caused by what virus? How transmitted?
Lentivirus
- causes lifelong infection of mononucs
- long incubation period
- direct or milk transmission
CS of OPP
- progressive joint swelling
- pneumonia
- aseptic mastitis “hard bag”
- thin ewe syndrome
Caprine Arthritis Encephalitis (CAE) caused by what virus? How transmitted?
Retrovirus
- causes lifelong infection of mononucs
- direct, vertical, or milk transmission
CS of CAE
- often subclinical
- chronic polyarthritis
- leukoencephalomyelitis in kids
- interstitial pneumonia
- mastitis
- asymptomatic
Dx/Tx/Prevent of CAE
Dx: serology, AGID, ELISA, PCR, mononuclear inflammation in synovial fluid
Tx: none
Prevent: pasteurized colostrum/milk infected animals
Toxic dose of lidocaine in ruminants
10 mg/kg
Toxic dose of xylazine in SR
0.2 mg/kg (1 mg/10 lbs)
