Every few years I hear a story or receive an email about veterinarians handling a horse with rabies. These accounts are rare, but they’re usually disturbing--sometimes because the animal becomes very dangerous (“ furious rabies”), and other times because the case masquerades as another illness and confirmation of rabies comes as a surprise at necropsy (this is the more common form in livestock, also called “dumb rabies”).
The take-home that I get from every single story is that horse owners and veterinarians should be on alert for certain--and sometimes bizarre—clinical signs; they should be careful about how they manage horses with these signs; and (most importantly) owners should have their horses vaccinated to prevent contracting rabies in the first place.
The case I heard about recently was a 16-year-old stud pony that was acting erratic and biting at a wound on his chest, which concerned the owners. The veterinarian explained to me she thought there might be something caught in this pony’s chest wound that was making him very uncomfortable. The vet told me, “He was so agitated the owner—an adult male—had trouble holding him. Looking back, that level of agitation and wanting to get his mouth on something should have alerted me. There’s always the excuse not to think of rabies, but looking back, that’s a signal I could’ve been more attuned to.”
Attempts to alleviate the pony’s apparent discomfort (with painkillers) and keep him from injuring himself further and allow the wounds to heal (converting an old plastic bucket into a bib to keep him from accessing his chest) failed, and the horse’s aggressiveness worsened. In the days following the initial vet visit, the pony eventually attacked the owner in the field. The vet explained to me that when the owners called and asked her to euthanize the horse, “That was the moment that I said, ‘You know, it’s pretty far-fetched but we’ve got to start thinking about this (rabies).’”
Upon return to the farm, she recounted, “This beautiful pony stallion very quietly has his head down, but when I reached out for him, he came up at me, teeth bared, staggering, ataxic (meaning he was incoordinated), delirious, fell to his side, reached back and started chewing on his hind leg.” State veterinary officials examined the horse’s brain following euthanasia, which is the only way to confirm rabies infection.
After rabies confirmation the owners underwent postexposure prophylaxis, and the veterinarian vaccinated the other animals on the property. These animals were quarantined for several months without incident; the quarantine has now been lifted.
Here are some things this veterinarian suggests horse owners and veterinarians remember about rabies after her close encounter:
- Vaccinate your horse against rabies: The disease is considered nearly 100% fatal in any mammalian species. “There is such a good, valid rabies vaccine for horses. It’s there, it’s not expensive, and it saves lives. It should be in your core vaccination schedule.”
- Realize that even a stalled horse can get rabies: I’ve heard of a scenario in which more than 30 horses were exposed via a rabid barn cat. Keep in mind that the primary wildlife reservoirs for rabies virus in the United States are raccoons, skunks, foxes, and bats. Effective vaccines are available for horses, dogs, cats, ferrets, cattle, and sheep.
- Watch for nonspecific clinical signs that “raise a red flag”: “If a horse’s agitation does not regress after treatment and/or if the animal is self-mutilating, or, on the other hand, if a horse seems to be mentally withdrawn (sometimes seen in cases of dumb rabies),” be concerned.
- Rabies should always be considered a “rule out” with any neurologic disease.
- If you or your veterinarian suspects rabies: Don’t euthanize the horse by gunshot to the head—the brain must be intact for necropsy. “They need to have the animal euthanized and send (the head) to the lab.”
- If rabies is/has been on your mind, and the animal dies or is euthanized: Get it tested. Due to rabies’ public health impact, most states don’t charge for testing.
- If you suspect you’ve been exposed: Don’t take any chances. See a doctor for postexposure prophylaxis series; oftentimes insurance pays for it. Except for the very rare circumstance, rabies is fatal. If you’re a veterinarian, have your titers checked every 18 months to two years to determine your level of protection.
If you’ve been in contact with a rabid horse’s water supply and feed buckets: Contact your physician for postexposure prophylaxis, and consider that the horse’s stablemates may have been exposed by sharing these items.
Finally, she says not to rely on the “hydrophobia” description/definition of rabies. “This horse drank water the day I put him down. (Fear of water) is not an accurate measure and may happen more often in dogs and cats. It’s not the same in every animal (species).”
While this pony’s signs were very apparent, sometimes a case looks more like this: a bevy of veterinarians and veterinary students have examined the mouth of a listless horse without an appetite. Before rabies is raised as a possibility, as many as dozens of clinicians, students, and staff, have looked in the horse’s mouth, and come in contact with the saliva. After the horse is euthanized, the veterinary pathologist confirms rabies and then the dozens of people exposed require prophylactic vaccinations.
Both cases are pretty awful, and both are preventable. Have your horses vaccinated annually and be wary of odd behavior in sick unvaccinated animals. Learn more about rabies in this archived webinar on TheHorse.com. Sign in/registration are required, but they’re free.
What’s your experience with rabies? Have you ever found a rabid wild animal on your farm?
(Many thanks to Kim Gemeinhardt, DVM, for relaying her rabies story.)