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18 Cards in this Set
- Front
- Back
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ddx for acute diarrhea in adult ruminants
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simple indigestion: most common
rumen acidosis BVD mucosal dz salmonellosis winter dysentery coccidiosis septic or toxic conditions xylazine administration surgical diseases (ex. LDA) stress |
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simple indigestion
a. etiology b. signs |
a. abrupt dietary change --> alterations in rumen flora
b. ↓ appetite, ↓ milk production, rumen hypomotility, mild bloat, abnormal feces (from scant & dry to watery) multiple animals generally affected signs usually transient |
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rumen acidosis
a. etiology |
a. grain overload (too much fermentable carbohydrate)
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bovine viral diarrhea (BVD)
a. etiology b. transmission c. pathophysiology |
a. pestivirus
biotypes -non-cytopathic: don’t cause visible degenerative lesions to cells grown in tissue culture (> 90% of BVD isolates) -cytopathic: do cause lesions genotype -type 2 strains often assoc. w/ outbreaks of severe, acute dz b. direct contact w/ secretions (nasal, oral, genital) of viremic animals c. replicates w/in lymphocytes & MPS --> viremia virus can colonize GI, respiratory, & repro tracts |
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BVD
a. clinical signs b. secondary complications |
a. most common: subclinical infection or acute, mild & transient signs
oral erosions (hallmark), diarrhea, fever, ↓ feed intake, ↓ milk production b. immunosuppression -transient leukopenia & lymphopenia --> ↓ resistance to infection (esp. respiratory dz) hemorrhage: some strains cause marked thrombocytopenia fetal disease/death |
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BVD: fetal dz
What is the result if fetus affected: a. during 1st 100 d. of gestation b. 60-180 d. of gestation c. before d. 125 of gestation d. after d. 180 of gestation |
a. early embryonic death
b. congenital defects: cerebellar hypoplasia**, etc. c. persistent infection of calf OR abortion persistently infected: sees virus as “self” Ag d. normal seropositive calf |
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BVD
a. dx: acute b. dx: chronic c. tx d. prevention |
a. gold standard: virus isolation (whole blood)
necropsy (necrosis of Peyer’s patches), signs (esp. oral erosions), serology b. skin bx: immunohistochemistry c. supportive care: fluids, ABs to tx or prevent 2º infections (most recover) cull PI calves immediately d. vaccination -cattle should be vaccinated at least once w/ MLV: must be after weaning (4-6 mo.) - long lasting immunity, cheap -do cause transient immunosuppression & viremia & some can cause abortion -can use some MLV vaccines in pregnant cows |
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mucosal dz
a. pathophysiology b. signs c. tx |
a. fetus must be exposed in utero to non-cytopathic strain at <125 d. of gestation & become persistently infected
PI calf later exposed to antigenically similar cytopathic strain of virus calf unable to mount immune response --> severe cytopathic lesions b. acute & always fatal (5-7 d.) fever, severe mucosal erosions, hypersalivation, profuse diarrhea, coronary band lesions, skin erosions c. euthanasia |
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salmonellosis
a. epidemiology b. transmission c. signs |
a. diary > beef: intensive housing predisposes to spread of infection & carrier animals more common in dairies
prevalence ↑ w/ herd size b. fecal-oral (contaminated food or water; : use of unsterilized animal & fish byproducts c. most infections subclinical w/ intermittent fecal shedding from prolonged periods peracute septicemia: sudden death, endotoxemia, abortion common acute enteritis: fever, anorexia, bloody diarrhea, dehydration, abdominal pain, endotoxemia chronic enteritis: chronic or intermittent diarrhea |
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salmonellosis
a. dx b. tx |
a. repeated fecal cultures
serology: herd dx b. supportive care, ABs, NSAIDs |
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winter dysentery
a. etiology b. epidemiology c. signs d. tx |
a. coronavirus
b. dairy cattle > 2 yo high morbidity, low mortality c. acute, profuse, transient diarrhea (often dark or bloody), ↓ milk production d. supportive |
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ddx for chronic diarrhea
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Johne's dz
ostertagiasis molybendosis/secondary copper deficiency LSA amyloidosis abdominal fat necrosis salmonellosis |
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Johne's dz
a. etiology b. epidemiology c. transmission |
a. Mycobacterium avium subspecies paratuberculosis
b. any ruminant, but esp. large dairy herds animals usually affected during 1st few months of life c. ingestion (fecal-oral or milk/colostrum), transplacental long incubation time: 1.5-2 yrs |
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Johne's dz
a. pathophysiology b. signs in cattle c. signs in small ruminants d. clin path e. tx |
a. bacteria colonize ileum, cecum, & ileocecal ln’s & with time spreads w/in GI tract --> granulomatous enteritis & lymphadenitis --> impaired absorption of nutrients --> PLE
organism can also spread via MPs to mammary gland & uterus shed in colostrum, milk, semen, feces infected animals may be not clinical & not shedding, shedding but not clinical, or shedding & clinical b. chronic, watery diarrhea, progressive wt. loss despite excellent appetite c. chronic wt. loss, usually no diarrhea d. hypoproteinemia, hypoalbuminemia small ruminants: anemia e. euthanasia |
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What are some methods by which Johne's dz can be diagnosed?
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hx & signs: presumptive dx: ruminant > 2 yo w/ chronic diarrhea & wt. loss despite good appetite, esp. if also hypoproteinemic, hypoalbuminemic
fecal culture: herd monitoring acid fast stain of fresh feces: individual animals (clumps of bacilli) PCR (feces) ELISA: herd basis AGID: individuals (positive result very indicative of Johne’s dz (good specificity), but negative doesn’t rule it out (low sensitivity)) laparotomy: gold standard for valuable animals (definitive dx: presence of acid-fast bacilli in ileum or ileocecal ln’s (bx)) necropsy |
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Johne's dz
a. prevention: dairy b. prevention: beef & sheep c. test & cull programs d. vaccination |
a. minimize exposure of newborn calves to M. paraTB
b. rotate pastures, avoid overcrowding c. backbone of most state certification programs common to use ELISA for “herd screen” & fecal culture all ELISA positives to confirm d. should NOT be part of control or eradication program -vaccine interferes w/ both TB & JD serology -doesn’t prevent infection or shedding, but may ↓ clinical dz -studies proving efficacy are lacking |
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ostertagiasis
a. epidemiology b. type 1 c. type 2 |
a. most common in young (< 2 yo), immunity develops w/ age (maybe not in goats)
b. assoc. w/ high pasture warm burden (summer & fall) c. assoc. w/ emergence of hypobiotic larvae in abomasum (spring) |
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ostertagiasis
a. signs b. dx c. tx |
a. diarrhea, ↓ feed intake, rough hair coat, ventral edema (bottle jaw) d/t hypoproteinemia
b. fecal > 2K eggs/gram c. deworming program |
