Viral Outbreak Puts Arizona Horse Community on Alert

When my kids were in 4-H, we acquired two horses. They're both mustang and who-knows-what, and they're long past their prime.

That said, I love these expensive lawn ornaments, and I would be devastated if they got sick. Both of my horses are retired, so they don't get out much anymore, but we have a lot of friends who take their horses to events all across the county. That's about to change, for a while at least.

Horse owners across Arizona are on high alert as Equine Herpesvirus (EHV-1) continues to spread across the West. The outbreak has led to the cancellation of equine events, and facilities are beginning to enforce strict biosecurity measures, reminiscent of the precautions we took during the COVID-19 shutdown for humans a few years back.

Get our free mobile app

Where Did the Outbreak Start?

According to the USDA, the outbreak originated at major equestrian events in Texas and Oklahoma in early November. Cases began spreading across multiple states, including Louisiana, Colorado, New Mexico, Washington, and South Dakota. The virus is now in Arizona.

Is the Equine Herpesvirus in Arizona?

Arizona confirmed its first cases in Maricopa County, according to Equus Magazine. Three horses tested positive for the virus but showed no symptoms. Now, a horse in Pinal County developed neurological signs, making this Arizona's first serious case.

READ MORE: These Things Are Illegal Around Horses in Arizona

What Horse Events are Being Cancelled?

Equine events are being cancelled and postponed across Arizona. According to the website, the Desert Classic Horse Show in Scottsdale, which was scheduled for December 4th through the 7th, has been cancelled until further notice. Across the state, rodeos and roping competitions have been postponed.

What Precautions Should Horse Owners Take?

Veterinarians are urging horse owners to quarantine new horses and other equines, disinfect all their tack and water buckets, and monitor temperatures twice daily if there's any chance of exposure.

While humans can't catch this virus, they can act as "mechanical carriers", which means humans can transmit the virus to horses and other equines. The virus can be spread through contaminated hands, clothing, boots, or grooming tools, and then the virus can be transferred from one horse to another

A publication from the American Association of Equine Practitioners advises that the virus can survive on tack, trailers, feed, water buckets, and clothing for up to 7 days under normal conditions and up to 1 month in certain environments.

Professionals like farriers and veterinarians who work with other equines should take precautions, as well.

READ MORE: Screwworm Threatens Arizona Livestock and Pets: USDA Acts Fast

What are the Signs of EHV-1 in Horses?

EHV-1 can cause respiratory illness, abortions in broodmares, and the dangerous neurologic form known as equine herpes myeloencephalopathy (EHM).

According to the USDA, horsekeepers should watch for these clinical signs of the virus in horses, even if the horses don't yet appear ill. The signs include:

• Fever
• Difficulty urinating
• Nasal discharge
• Cough
• Depression
• Head tilt
• Loss of tail tone
• Stumbling or weakness in the hind limbs that progresses to all limbs
• Lying down and unable to get back up
• Abortion in pregnant mares

Are All Equines at Risk of the Virus?

Yes, all equines are at risk of contracting the virus, as well as camelids. Care should be taken around:

• Horses
• Donkeys and mules
• Llamas and alpacas
• Zebras

If you suspect your horse or other equine may be sick, quarantine the animal and consult a veterinarian.