April 27, 2020 – Dr. Brian Johnson Washington State Veterinarian:
A King County horse tested positive for Equine Herpes Virus (EHV) last week after showing mild signs of the disease. Results of tests on three other horses at the 30-horse facility where it was stabled are pending.
Equine Herpes Virus (EHV) is a potentially fatal animal disease in the United States.
It not only has the potential to affect horse health but, because it’s highly contagious and requires lengthy quarantines or cancellations of events like rodeos and fairs, the economic consequences can be equally devastating.
The infected horse in King County is receiving treatment and the facility is now under a minimum 14-day quarantine to be lifted only after WSDA confirms that there are no more signs of the disease.
The horse will remain in quarantine until two negative PCR tests, which look for traces of the viral genetic code, can be verified. The facility has cooperated fully with the quarantine order and is working to ensure strict biosecurity measures are in place.
The case should serve as a reminder to apply appropriate biosecurity measures, update vaccinations, and be vigilant for signs of the disease.
What to watch for
Given the infectious nature of EHV, WSDA asks horse owners to follow these recommendations.
Watch your horse for signs of possible infection including:
• Fever of 101.5 F or higher.
• Discharge from the eyes or nose.
• Respiratory symptoms.
• Swelling of the limbs.
• Spontaneous abortions.
• Neurological signs such as an unsteady gait, weakness, urine dripping, lack of tail tone and recumbency.
Check your horse’s temperature twice daily, ideally first thing in the morning and last thing at night. Also, check before administering medications since some can lower body temperature.
Notify your veterinarian immediately if you detect any of the symptoms above. Your veterinarian may want to take nasal swabs for virus detection or blood samples for evidence of exposure to EHV-1.