Wildtype EHV-1 detected in one Snohomish County horse, quarantine order issued

  |   Animal Health


The Washington State Department of Agriculture (WSDA) has quarantined a Snohomish County facility near Arlington after a single laboratory-verified case of equine herpes virus EHV-1, non-neuropathogenic strain, was detected there.

This “wildtype” strain of EHV-1 tends to be less contagious than the neuropathogenic type.

On August 3, 2018 one horse at the facility tested positive for the virus.  This horse is isolated on the premises and WSDA has quarantined the facility.  Test results for a second, suspect horse are pending.  The quarantine will last until 14 days after WSDA confirms no further signs of the disease and the horses test negative.

The facility has cooperated fully with the quarantine order and is working to ensure strict biosecurity measures are in place. WSDA is tracing movements of horses off the premises and may issue additional quarantine orders if needed.

Given the infectious nature of EHV-1, WSDA urges horse owners to follow the recommendations below.

Watch your horse for signs of possible infection such as:

  • Fever of 102.5 F or higher
  • Discharge from the eyes or nose
  • Respiratory symptoms
  • Swelling of the limbs
  • Spontaneous abortions
  • Neurological signs such as 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 as some can lower body temperature, masking fever.

Notify your veterinarian immediately if you detect any of the symptoms above. Your veterinarian may wish to take nasal swabs for virus detection or blood samples for serological evidence of exposure to EHV-1.

When the virus is detected, WSDA and local veterinarians work closely with affected communities to ensure the best biosecurity standards are practiced. For more tips on keeping your own horses safe through good biosecurity practices, please see the WSDA web site for Equine Biosecurity.

The time between exposure and illness from EHV-1 varies from two to 14 days. By self-quarantining animals with possible symptoms, practicing good biosecurity and contacting your veterinarian as soon as you suspect possible symptoms, you can help prevent the spread of this virus.

By Dr. Brian Joseph, State Veterinarian, Washington State Department of Agriculture


Posted August 7. 2018