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Lab Results Returned for Far West Horses

Samples from three of the affected horses were tested at the Oregon State University Veterinary Diagnostic Lab today and were confirmed to be positive for Equine Influenza A Virus. The samples were negative for Equine Herpes Virus 1 & 4 and for Equine Viral Arteritis. The remainder of the samples will be tested via Merck's Equine Respiratory Pathogen Surveillance Program at UC Davis Veterinary Diagnostic Lab tomorrow, but we expect the results will confirm OSU's.

All affected horses are recovering with only symptomatic treatment, though the number of cases has increased to approximately the mid 20s that we are aware of as of today.

The Equine Influenza Virus (EIV) can persist in the environment (on inanimate objects) for only about 2-3 days, fortunately. Infected horses should be quarantined for 21 days and any exposed but non symptomatic horses can be quarantined for 14 days. This virus is very contagious, and can travel up to 50 yards through the air, so quarantine arrangement should take this into account.

Infected horses should be rested from work for one week for every day of fever they experience or there is risk of cardiac muscle damage.

Intranasal vaccines will provide the most rapid protection, usually by Day 5, against influenza. Intramuscular influenza vaccines are effective as well, but take longer (about 2 weeks) to provide protection. Make sure your vaccine carries the more recent strains (A2/Clade 1/North American).

Here is a great info sheet for horse owners:
And for those who enjoy the technical details:


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