The Most Terrifying Disease That Can Affect a Horse ...

It is possibly the most terrifying disease that can affect horses. It causes neurological impairment and behavior changes, it can be transmitted to humans, and it causes death in 100% of cases within 48 hours of the demonstration of clinical signs. Even scarier yet, there is a relatively large subset of horse owners who do not vaccinate their horses for this entirely preventable condition.

What is this terrible disease? RABIES. Why don’t some horse owners vaccinate their horses for the condition? BEATS ME!

What is rabies?

Rabies is a virus that can infect all warm-blooded animals, including people. Its primary route of transmission is through the bite of an infected mammal, but it can be transmitted when fresh saliva from an infected animal comes in contact with a wound or mucous membranes (Source: Rabies surveillance in the United States during 2014).

Once an animal becomes infected with rabies, it can take from 2-6 weeks before clinical signs are seen. Once you observe the clinical signs, most animals will die in approximately 48 hours.

Why is my horse at risk?

According to the Centers for Disease Control and Prevention, there were 6,034 reported cases of rabies in the United States in 2014. Of those cases, 92.6% were wild animals with the rest of the cases being domestic animals or people. Of the wild animals affected, 30% were raccoons, 29% bats, 26% skunks, 5% foxes, and < 2% other animals. So as much as this disease does not seem like much of a risk, rabies continues to be seen within the United States.

Horses that are more at risk include those with 24-hour access to pasture and wildlife. In 2014, Wisconsin saw 27 cases positive for rabies, all of them wildlife cases in which 26 of those were infected bats and one of which was an infected fox.

What does rabies in horses look like?

Classically, rabies can come in two forms:

  1. Dumb Form - Causing depression and stupor OR
  2. Furious Form - Causes mania. In horses, this form is extremely dangerous.

However, based on the opinion of many equine practitioners, rabies in the horse can look like anything with clinical signs including fever, inappetence, colic, blindness, inability to eat, self-mutilation, muscle twitching, lameness, incoordination, incontinence, paralysis, or sudden death. In any horse that is displaying neurologic signs and that is not up to date on vaccinations, rabies should be considered a possibility.

For more information on what rabies looks like in horses, see this article from the American Association of Equine Practitioners: Rabies Has Many Faces

What do I do if I think I have been exposed to a rabid horse?

For any individual that has not previously been vaccinated against rabies and has had contact with a rabid patient, post-exposure prophylaxis should be performed as quickly as possible. Post-exposure prophylaxis includes cleansing bite wounds with soap and water, infiltrating wounds with the human rabies immune globulin (HRIG), and receiving 4 doses of rabies vaccine over the next 14 days.

What do I do if my horse has been exposed to a rabid animal?

For horses that have previously been vaccinated for rabies, post-exposure prophylaxis is recommended and should be performed promptly once the exposure is suspected. The animal should then be observed closely for the following 3 to 6 months. 

If your horse has not been vaccinated previously, post-exposure vaccination is of little value.

What can I do to prevent rabies exposure to my horse?

ALL horses are recommended to be vaccinated against rabies every year. Vaccination can be performed at any time of the year and, in my experience, is unlikely to cause a vaccine reaction. We will often recommend vaccinating horses for rabies in the fall, as it nicely spreads out the number of antigens we are giving a horse at one time (separate from spring boosters) and because it comes as a combination vaccination with the vaccination against Potomac Horse Fever

Badger Equine uses Equine POTOMAVAC® + IMRAB®, a combination vaccine that provides powerful protection against two potentially fatal diseases in horses: Potomac horse fever and rabies. Equine POTOMAVAC® + IMRAB® can be administered to healthy horses and foals 3 months of age and older. After the primary vaccination and booster, annual revaccination is recommended.

Please contact us if you have any questions regarding rabies vaccination or to schedule your appointment.

References:

  1. Monroe et al, 2016 “Rabies Surveillance in the United States during 2014” JAVMA, 248:7 (777-788).

  2. American Association of Equine Practitioners “A Review of Equine Zoonotic Disease: Risks in Veterinary Medicine” 2002.