Bovine Flash Notes - Scrapie Flashcards
what animals are most commonly affected by scrapie?
adult, black faced breeds in the USA (96% of cases), rarely seen in goats, usually within 2 years of age with an incubation period of 2-5 years
T/F: death will occur within months once clinical signs of scrapie are present
TRUE
what clinical signs are seen with scrapie?
intense pruritus (70%) wool loss from rubbing/hypersensitivity, weight loss with normal appetite, & progressive neurologic signs - clinical signs will vary!!!!
how is scrapie diagnosed?
must detect prion proteins in tissue
what is the gold standard test for diagnosing scrapie? what are the other diagnostic tests used to diagnose scrapie?
ICH on brain tissue, most often obex, or cerebellum for atypical scrapie - histopathyology on vacuoles/plaques, western blot when tissues are autolyzed, IHC on a biopsy of the 3rd eyelid
how is scrapie treated?
no treatment - euthanize
what is the prognosis of scrapie?
grave - always fatal
how is scrapie prevented?
breed only genetically resistant sheep, do not feed ruminant proteins to ruminants, maintain closed herds, euthanize positive sheep, follow eradicate scrapie guidelines/mandatory eradication program, & incinerate or use alkaline digestion to dispose of infected carcasses
T/F: scrapie is a transmissible spongiform encephalopathy which is a REPORTABLE disease
TRUE
what causes transmissible spongiform encephalopathies?
misfolded versions of normal cellular proteins - not foreign proteins, so there is NO IMMUNE RESPONSE
what tissues should be submitted for the diagnosis of scrapie? what antemortem tests are used?
brain tissue, most often obex, or cerebellum for atypical scrapie - antemortem, biopsy of lymphoid tissue from 3rd eyelid, biopsy of tonsils, & biopsy of placenta
what tests are used for screening or confirmation of infection from scrapie?
ELISA for screening - on brain & lymphoid tissues - western blot is used when tisues are autolyzed
