Bovine Flash Notes - BLV Flashcards
what is the classic case presentation of bovine leukosis?
adult dairy cows with weight loss, decreased milk production, off feed, +/- external masses, & BLV positive
what are the 2 syndromes seen of BLV?
sporadic & enzootic leukosis - others are lymphosarcoma & leukemia
what is sporadic BLV?
RARE!!! BLV negative cows, juvenile <6 months, thymic 6-24 months, & cutaneous 1-3 years
what is enzootic BLV?
all are BLV positive!!!!! most are subclinical infections with less than 5% developing illness/tumors
what are the 4 scenarios in adult cows with enzootic BLV?
no infection - genetic resistance, infection with positive antibody titers but no clinical signs (carriers), infection & benign persistent lymphocytosis (PL), & multicentric lymphoma (LS) +/- PL
T/F: most cows with enzootic BLV have subclinical infections with less than 5% of them that develop illness/tumors
TRUE
which cows are more commonly affected by BLV, dairy or beef?
dairy»_space;»> beef
what are the clinical signs associated with lymphosarcoma from BLV?
often vague at first - weight loss, decreased appetite, decreased production, no fever, enlarged peripheral lymphnodes in 75-90% of cases
how long do animals with BLV lymphosarcoma live after clinical signs become apparent?
short once signs are apparent - weeks to months
what are the tests of choice for diagnosing BLV? how are they used?
serologic tests are diagnostic for BLV infection - AGID is the first test used (not positive until 3-12 weeks of age), & ELISA can ID infection in herds with low prevalence & has replaced AGID in most labs
what treatment is recommended for cows with BLV?
BLV is a retrovirus, so infection is permanent - no treatment, cull/slaughter in most cases
how is BLV prevented?
ID infected cows/calves & remove them, use colostrum from BLV negative cows only, & feed calves pasteurized milk or milk replacer
