Acute Diarrhea Flashcards
what species and serovars of salmonella cause acute diarrhea in cows?
salmonella enterica, with many serovars including typhimurium, dublin, newport
T or F, salmonella only causes diarrhea
false, it causes many things like abortion, septicemia, pneumonia, etc
what clinical signs do you see with salmonella?
any age cow, pyrexia and diarrhea, can contain blood or fibrin, can result in septicemia/endotexemia
you are examining a cow that has watery mucoid diarrhea. This cow’s temp is 39. what do you suspect and what do you do next? How are you going to treat this cow?
suspect salmonella; can do an aerobic culture of the feces or do PCR to confirm. ELISA also available for S dublin
treatment: fluids and NSAIDs, antibiotic use controversial (only consider in cases of septicemia or calves maybe?), if you’re gonna use one use TMPS
how does salmonella spread, and who is most at risk? What can you to do prevent it?
cow to cow spread, carrier states possible, transition and fresh cows most at risk or any that have a suppressed immune system like calves, birds and rodents can also carry the disease
prevented via good hygeine (regular biosecurity protocols, sometimes hard to do), vaccines also available
describe what winter dysentery is
caused by covine coronavirus (BCov), has high morbidity low mortality, is a fairly short lived disease, usually in housed cattle over the winter
common clinical signs of winter dysentery
decreased appetite, bloody diarrhea, pyrexia, reduced milk production, resolved in 24-36 hours
you are called out to a farm in January that has 2 month old calves with fevers and blood diarrhea and are also not eating. What will you do next?
probs winter dysentery/bovine coronavirus
can do PCR of the feces, antibody ELISA (paired sample)
supportive therapy only (if secondary infections, then reach for antibiotics)
coccidiosis is caused by
eimeria parasite (not all species are pathogenic and almost no labs test for specific species identification, remember that)
common history and presentation of cow with coccidiosis
younger animals but not neonates (PPP is 15-20 days), with large intestinal diarrhea (straining, fresh blood, mucus)
what is nervous coccidiosis?
neurologic signs from coccidiosis infection, spasms, nystagmus, seizures, reported in NA feedlots only
you are looking at a 2 month old cow that is straining to poop, and when it does pass feces there is fresh red blood and mucus in the feces. what do you do next?
im thinking coccidiosis, so I want to check for oocysts in the feces
treatment is supportive; coccidiostats can reduce shedding but can’t really be used theraputically, more used prophylactically
true or false: coccidia species don’t last long in the environment
FALSE they are VERY persistent in the environment
Parasitic Gastroenteritis is more common in what kind of animal?
grazing animals with poor growth
what kind of virus is BVDV? does it always cause diarrhea?
pestivirus
and no, it usually does NOT cause diarrhea actually which is confusing given the name
describe the difference between type 1 and type 2 BVDV in CALVES
type 1 (nCP): immunisuppression, makes other diseases worse, may get diarrhea, then antibodies develop and they get strong immunity
type 2 (CP): severe acute/peracute infection, sometimes found dead, severe thrombocytopenia, high morbid &mortal
describe the difference between type 1 and type 2 BVDV in NON PREGNANT adult cow
type 1: mild fever, immunosuppression, virus is shed, antibodies are produced and get strong immunity and stop shedding
type 2: severe acute/peracute infection, sometimes found dead, severe thrombocytopenia, high morbid &mortal
describe the difference between type 1 and type 2 BVDV in the BULL
type 1: mild fever, immunosuppression, virus is shed, antibodies are produced and get strong immunity and stop shedding (MAY PERSIST IN SEMEN)
type 2: severe acute/peracute infection, sometimes found dead, severe thrombocytopenia, high morbid &mortal
describe the difference between type 1 and type 2 BVDV in the PREGNANT COW
type 1: mild fever, immunosuppression, virus is shed, antibodies are produced and get strong immunity and stop shedding, may cause loss of pregnancy
type 2: lose the calf for sure, severe acute/peracute infection, sometimes found dead, severe thrombocytopenia, high morbid & mortal
describe the outcomes if a calf IN UTERO is exposed to BVDV type 1 for each of the following conditions:
- early gestation, <100 days
- mid gestation, 100-150 days
- late gestation >150 days
- BEFORE 125 days if survives
- early gestation: lose the fetus, resorption, mummification, etc
- mid gestation: congenital defects such as cerebellar hypoplasia or congenital cataracts
- late gestation: possible abortion or no effect at all, normal calf
- before 125 days if survives: fetal immune system not developed–:persistently infected calf=BAD NEWS
how is a PI calf created?
if the dam is infected with the virus before 125 days gestation, the fetus has no immune system and therefore no defence against the virus, the calf recognizes the virus as self, the virus is found in almost all tissues, and NO antibodies will develop.
what is the primary reservoir for BVD infection?
PI calves
Do PI calves appear sick?
they can be “poor doers” but they can also appear completely normal!
what is Mucosal Disease?
when BVDV in a PI calf mutates to a cytopathogenic strain, and since they have no immunity, they develop mucosal disease. it is severe and untreatable
Clinical signs of Mucosal Disease?
fever, depression, oral mucosa lesions, diarrhea. BUT remember this is not contagious and does not spread from calf to calf
what are the tests you can use to diagnose BVD?
antigen (virus) test: virus isolation via blood, immunohistochemistry on ear notch, antigen ELISA, PCR pooled blood, PCR bulk milk
antibody test: virus neutralization, blood ELISA
explain what each of these means for BVDV:
antigen neg, antibody neg
antigen pos, antibody neg
antigen neg, antibody pos
antigen pos, antibody pos
- naive cow, has not been exposed
- PI calf, or an infected animal that hasn’t had time to develop antibodies yet
- exposed and then recovered, either via vaccine or exposure to virus
- acute infection
what are some things to look for at a herd level if you suspect BVD?
poor calf health, BRD or diarrhea present, repro performance is suboptimal
what are some techniques to manage BVD at the herd level?
screen youngstock, do bulk milk tests in dairy herds, routein ear tagging, if PI is confirmed, look for others and screen all adults, and remove all PIs from the herd
how can you prevent BVD at the herd level?
vaccinate: will reduce PI creation and losses, make sure to vaccinate before first breeding
