Bovine Flash Notes - Johne's Disease Flashcards
what is the classic case presentation of a cow with johne’s?
thin, older dairy cow with chronic diarrhea & a good appetite at first
hat are the main clinical signs seen in a cow with johne’s?
chronic/intermittent diarrhea, appetite is good at first, milk production drops with protein levels, weight loss, submandibular/ventral edema
what are the main clinical signs seen in sheep/goats with johne’s?
weight loss!!!! diarrhea is not common - wool breaks easily
what is seen on necropsy of a cow with johne’s?
thickened, corrugated intestine, especially terminal ileum, enlarged/edematous lymph nodes
what is seen on necropsy of sheep/goats with johne’s?
foci of caseation with calcification of intestinal wall & lymph nodes, enlarged distal mesenteric lymph nodes
what is the number one mode of transmission of johne’s? when does shedding begin?
fecal oral!!!! shedding begins prior to the onset of clinical signs
what is a super shedder of johne’s?
cows that can pass up to 10^5 CFU/grams in their feces
T/F: if clinical signs of johne’s are present, death is inevitable
TRUE
what is the test of choice for diagnosing johne’s? what government agency is approved to test for it?
culture on feces or postmortem sample - USDA approved labs!!!
what is the agent that causes johne’s disease?
mycobacterium avium sub species paratuberculosis
what is the most appropriate action to take if a cow tests positive for johne’s disease?
cull it
how long can mycobacterium avium sub species paratuberculosis survive in the soil?
more than 1 year - longer in water & survives pasteurization
what animals are the number one source of johne’s?
silent shedders
T/F: johne’s disease primarily affects dairy cattle
TRUE
