Small Ruminant Viruses Flashcards
What are the viral characteristics of bluetongue disease?
reoviridae, RNA, segemented
How is blue tongue transmitted?
arbovirus
Where does bluetongue occur in the world?
tropics and subtropics
What is the most important economic loss of bluetongue?
major trade barrier
What insect transmits blue tongue virus?
culicoides
What is the reservoir for bluetongue virus?
subclinically infected cattle
What are the viral characteristics of caprine arthritis-encephalitis?
retroviridae - RNA, enveloped
What are the 2 syndromes associated with caprine arthritis-encephalitis and at what age do they occur?
encephalomyelitis in kids (2-4 months)
arthritis - older than 1 year
What are the clinical signs associated with caprine - A-E?
lameness, wasting, but afebrile, alert, good appetite and sight, ascending paralysis, paddling
What are the arthritis signs of caprine -A-E?
insidious onset over months/years, joints swollen and painful
Where will you find lesions in necropsy of goats with caprine-A-E?
focal malacia in WHITE matter
joint lesions are of proliferative sinovitis
pneumonia
How is caprine-A-E diagnosed?
antibody detection, test and remove
How is caprine-A-E controlled?
no vax, transmission thru colustrum - can pasteurize colostrum to prevent
What are the clinical signs of scrapie?
excitable, tremors, intense pruritus, deterioration over 1-6 months
What are the necropsy lesions associated with scrapie?
gray matter - vacuolation, no inflammation
What test can be used to diagnose scrapie?
IHC and western blot on CSF
What family is maedi?
retroviridae
What is maedi called in the US?
ovine progressive pneumonia
What are the clinical signs of maedi?
insidious onset, not recognized until 3 years old
jerking of head and flared nostrils, nasal discharge and cough, abort, immunosuppresion
What are the necropsy lesions associated with maedi?
lungs and LN - HOMOGENOUSLY consolidated nodules, lungs don’t collapse
What is the most commonly used test for maedi?
antibody ELISA
What is a more sensitive test that can be used for maedi?
WB, PCR
How is maedi transmitted?
Directly and indrectly (not typical of retros)
How is maedi controlled?
avoiding transmission –> biting arthropods, surgical equipment mechanically
What family is ovine pulmonary adenomatosis?
retroviridae
What can not be used to diagnose ovine pulmonary adenomatosis?
cell culture - doesn’t grow on it
What is the incubation time for ovine pulmonary adenomatosis?
years, but shorter in lambs
How are the clinical signs of ovine pulmonary adenomatosis different from maedi?
large amounts of surfactant containing viscous fluid produced by tumor cells
Lesions in lung are nodular
What kind of tumors come from ovine pulmonary adenomatosis?
adenomas and adenocarcinomas - metastasis
Where is OPA secreted?
in saliva and respiratory secretions
What are 2 other names for Orf?
contagious ecthyma, scabby mouth
What viral family is Orf?
Poxviridae - replicates in cytoplasm
Where are scabby lesions found on the sheep?
muzzle, within the mouth esp lambs, rarely on eyelids, feet and teats
What makes Orf so hard to eradicate from a flock?
reinfection, chronic infections, resistance in environment
How can Orf be prevented?
ewes vaccinated weeks before lambing –> applied by scarified skin, short lived immunity
