▁B L V ▁causes ▁only ▁a ▁ben ign ▁mon on uc le osis - like ▁disease ▁in ▁cattle . ▁Only ▁some ▁animals ▁later ▁develop ▁a ▁B - cell ▁le uk emia ▁called ▁en zo otic ▁b ov ine ▁le uk osis . ▁Under ▁natural ▁conditions ▁the ▁disease ▁is ▁transm itted ▁mainly ▁by ▁milk ▁to ▁the ▁cal f . ▁ ▁The ▁variety ▁of ▁org ans ▁where ▁white ▁blood ▁cells ▁occur ▁explains ▁the ▁many ▁sympt oms : ▁en larg ement ▁of ▁super f icial ▁l ym ph ▁nodes , ▁a ▁dig est ive ▁form , ▁a ▁card iac ▁form , ▁a ▁nerv ous ▁form , ▁a ▁resp ir atory ▁form , ▁and ▁others . ▁L ym ph ▁node ▁en larg ement ▁is ▁often ▁an ▁early ▁clin ical ▁sign . ▁An ▁unexpected ▁clin ical ▁finding ▁is ▁pro tr usion ▁of ▁the ▁conj unct ival ▁memb rane , ▁due ▁to ▁en larg ement ▁of ▁retro - oc ular ▁l ym ph ▁nodes . ▁ ▁Di agn osis ▁Di agn osis ▁re lies ▁on ▁ag ar ▁gel ▁imm un od iff usion , ▁EL IS A ▁and ▁PC R . ▁Post - mort em ▁find ings ▁are ▁characteristic ▁and ▁include ▁w ides p read ▁white ▁tum ours ▁in ▁most ▁org ans . ▁ ▁B L V ▁in fection ▁in ▁humans ▁can ▁be ▁identified ▁by ▁testing ▁for ▁ant ib od ies ▁against ▁B L V ▁using ▁the ▁imm un ob lot ting ▁and ▁searching ▁for ▁ant ib od ies ▁against ▁the ▁pur ified ▁recom bin ant ▁p 2 4