In my role as news editor of The Horse and, it's my job to seek out current horse health happenings, find the details, and report back to you—our readers—as quickly and accurately as I can. That's not always easy—in some cases details from reliable sources are few and far between, or sometimes we really just don't know exactly what's happening yet—but something I've gotten plenty of practice at reporting on over the past few years is equine herpesvirus-1 (EHV-1).

In covering what feels like countless EHV-1 cases and chatting with numerous veterinarians, I've learned a fair amount about this potentially deadly disease. I know how horses contract the disease, and I know what biosecurity protocol I should follow to best protect my four-legged charges. But sometimes it takes a real life example for things to sink in. For instance, in early April animal health authorities said that a 22-year-old Thoroughbred mare from New Jersey who reportedly hadn't left her home farm in years was euthanized after she exhibited rapidly progressing neurologic signs; she later was confirmed to be EHV-1 positive.

Owners can take some simple steps to help protect their senior horses from contracting EHV-1, especially in animals such as Dorado that still regularly travel.

Photo: Erica Larson

Being a senior horse fanatic, I was saddened to hear that this old girl met such a devastating end; but being a (mildly neurotic) senior horse owner, I wondered if my parents and I are doing everything possible to protect our aging equids from contracting neurologic EHV-1 or developing signs of disease. So I caught up with a regular The Horse contributor and veterinarian Stacey Oke, DVM, MSc, to learn a little more about EHV-1 in senior horses.

First, yes, our older horses—specifically those ages 20 and up—are at an increased risk for developing neurologic EHV-1, she said, citing the American College of Veterinary Internal Medicine's Equine Herpesvirus-1 Consensus Statement. Yes, our seniors could be neurologic EHV-1 carriers (possibly for years without an owner having the slightest clue) and, yes, "herpesviruses can … spontaneously manifest to cause clinical disease and be spread to other horses without any warning," Dr. Oke said.

Next, she said, any horse—not just seniors—is at a higher risk of contracting the virus when they comingle with other horses at shows, trail rides, and other equine events.

"Sure, showing is fun, but it can be like taking a newborn baby to the local mom and tot play group with tons of runny-nosed kids running around, shoving toys in their mouths before sticking it in your baby's face," Dr. Oke explained. In short, you never know what other equids have been exposed to before they come in close contact with your horse.

This doesn't mean you shouldn't take older horses out and about; rather, just be smart when taking them out for adventures. Avoid letting them come in contact with other horses; don't share equipment (like buckets, brushes, or tack); and monitor horses' temperatures before, during, and after trips. Veterinarians also recommend isolating horses returning from travels in case they picked up a virus or disease while away from home and practicing good on-farm biosecurity during that time frame (disinfecting hands with soap or hand sanitizer after handling the horse, handling that animal last, and monitoring the horse for any signs of disease, among others).

And finally, Dr. Oke strongly recommended discussing EHV-1 vaccination with your veterinarian and vaccinating if he or she deems a certain horse at-risk. The currently available vaccines aren't labeled for protection against neurologic EHV-1, but they're labeled to provide protection against some forms of the virus. When considering vaccines, remember that each horse's situation should be carefully analyzed by a veterinarian before the decision to vaccinate or not is made; my 17-year-old OTTB Dorado gets vaccinated per his vet's orders because he travels to competitions and off-site schoolings several times throughout the year at which he could be exposed to the virus. However a veterinarian might determine that a senior horse in a closed herd might not require vaccination. Talk vaccinations over with your vet before making a decision either way.

I left the conversation with Dr. Oke more informed about EHV-1 and how it relates to senior horses, and better prepared to take steps to reduce my horses' risk of disease contraction.

Have you ever dealt with EHV-1 in a senior horse? What advice would you give to other horse owners about the disease?