WSDA Blog

On March 6, 2024 a horse in Skagit County tested positive for EHV-1, a wildtype strain rather than the neuropathogenic type. This case involves only one horse who presented with hind end weakness and urine dribbling and is still undergoing treatment. The farm is currently under quarantine and the owners are strictly adhering to biosecurity measures under the supervision of a private veterinarian, no other horses on the property are affected. The horse has been vaccinated within the last year.

While this development is concerning, it's important to highlight that the risk of spread is currently contained to this isolated case and this horse has not attended any shows or events. It is also a good reminder to avoid other sick horses and make sure your horse is up to date on vaccines. 

The Washington State Department of Agriculture (WSDA) has NOT mandated that shows and events be canceled or postponed in Skagit County, but event coordinators may make decisions based on THEIR biosecurity protocols or perceived risk. It's worth noting that this case is NOT related to the EHV outbreak in Spokane County in February of this year.

Understanding EHV

Equine Herpes Virus is a highly contagious viral disease affecting horses, with various forms ranging from respiratory issues to neurological complications. Neurological symptoms, known as Equine Herpesvirus Myeloencephalopathy (EHM), can be particularly severe and potentially fatal. Early detection and appropriate biosecurity measures are crucial in containing the spread of EHV. Horse owners should monitor their animals for signs of infection, including fever, respiratory symptoms, limb swelling, and neurological signs. In case of suspicion, it's essential to notify a veterinarian promptly for further evaluation. Timely intervention can help prevent the spread of the virus and mitigate its impact on both equine health and the broader equestrian community.

What to watch for 

Given the infectious nature of EHV-1, WSDA asks horse owners to follow these recommendations.
Watch your horse for signs of possible infection including:

• Fever of 101.5 F or higher. Taking temperatures routinely can help with early detection.
• 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.

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. The time between exposure and illness from EHV-1 can be as long as 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.
When the virus is detected, WSDA and local veterinarians work closely with affected communities to ensure the best biosecurity standards are practiced.

Update on Spokane County EHV outbreak

The EHV outbreak in Spokane County resulted in two quarantines associated with one farm. Multiple horses on the premises showed various forms of the disease, including respiratory, abortion, and neurologic symptoms (EHM). However, the last reported EHM case was on February 15, 2024. The owner of the affected farm was cooperative and implemented strict biosecurity measures that were overseen by WSDA field veterinarians. There is currently no evidence the disease spread to other facilities, and there is no history of the affected horses attending shows or events recently. The situation was monitored closely and the quarantine will be lifted March 10, 2024 (21 days after the last clinical signs of EHV).

It's essential for horse owners to remain vigilant, especially during this active season when horses are more likely to travel to public events.
For more information, contact WSDA's Animal Health Program or visit equinediseasecc.org/alerts.