Equine Respiratory Dz (I, II, III) Flashcards
Name the common Equine Resp Viral Diseases
EHV-1/4 (Equine Herpes Virus 1-4), EIA (Equine Invluenza Virus), EVAV (Equine Viral Arteritis Virus)
Describe clinical signs of Eq Resp Dz
Serous! nasal discharge, cough (elicited or spontaneous), fever, lethargy, exercise intolerance, inappetence, lymphadenopathy
What diagnosics distinguish between common resp pathogens
Serology (antibody testing - requires seroconversion! (2 samples with 4x increase in titers over time) Consider vacc. )
viral culture (slow, cumbersome, hard) PCR for viral DNA - widely available, can do big panel for common pathogens w/ one sample ELISA (for viral antigen, a few available)
Describe biosecurity for an infectious resp dz outbreak
- DONT BE A FOMITE!
- healthy, suspect, and sick pens/barns with no mixing
- seperate equipment (and ideally staff for sick and healthy groups, if not do healthy chores first, then sick, then shower)
Tx of Resp Dz (general)
Rest, NSAIDS, supportive therapy, fluids, +/- antibiotics if 2* bacterial dz, antivirals usually not warranted
To test or not to test?
Worthwhile to stop spread (shape biosecurity measures), change/add vacc protocol
Samples to collect
SERUM, Transtracheal wash, nasal swab, deep pharyngeal swab,
What does EHV-1 look like clinically?
Young horse with: Respiratory, ocular Dz, abortion, CNS disease sometimes
What does EHV-4 look like?
Young horse with: resp/oclular signs, some abortions
EHV-1 Abortion - how to tell?
fresh fetus, late term in breeding facility
EHV-1 signs in foals
no good tx, rapidly progressive viral pneuomonitis, die within 2 weeks
What is EHM?
Rare complication of EHV-1, CNS signs - hindlimb incoordination can progrerss to general paralysis, recovery is variable & dep on severity
Does EHV-1 cause respriatory signs?
ONLY in young horses, not preceding abortion, not all cases. Herpesvirus => think latency!
Can you eliminate EHV-1 from a population?
NO! Herpesvirus, by nature, can go latent. Which means it can be found in closed herds
Describe the pathogenesis of EHV-1
Virus shed by adult who’s stressed, youung weanling or so gets it via nasal secretions, virus goes to LN, infects Bs/Ts => cell associated viremia => infects endothelium and causes vasculitis (if in brain then does encephalopathy, if uterus does abortion)