Rabies: What Every Horse Owner Should Know

Equine rabies is a fatal disease. If a horse contracts rabies there is no second chance, and each year we are reminded of its impact. Two horses have died from rabies just since the end of July.[1] Neither was vaccinated.

With fewer than 100 cases of rabies reported in horses, donkeys and burros every year, it’s easy to disregard the disease. But while the incidence of equine rabies in the United States is low, the fatality rate is high – 100 percent. Furthermore, there is always the significant and serious potential for any infected animal to transmit the disease to humans. That’s why rabies vaccination is considered a core vaccine recommended by the American Association of Equine Practitioners – every horse should be vaccinated, every year.[2]

What is rabies?

Rabies is a virus that causes a neurological disease that can affect all mammals. When an animal is bitten, the virus migrates to the brain where it causes inflammation, known as encephalitis. It is rapidly progressive and invariably fatal. The incubation period – the time between the virus’ entry into the body and the onset of clinical signs – averages 2 to 9 weeks, but may be as long as 15 months.

Veterinarians often state that rabies can look like anything. While some horses exhibit intermittent or continuous signs of aggression, most infected horses are depressed or stuporous. Some may become anorexic and refuse to drink, while others will continue to eat and drink until shortly before death. Obscure lameness and incoordination are relatively common early signs of rabies.

Be extremely cautious and call your veterinarian immediately if your horse has any of the following signs:

  • Incoordination (ataxia)
  • Urinary incontinence
  • Poor performance
  • Difficulty swallowing
  • Lameness
  • Colic
  • Bizarre behavior ranging from stupor to aggression and self-mutilation
  • Abnormal vocalization
  • Paralysis

There is no definitive test to diagnose rabies in a live animal. A rabies diagnosis is often made only after death during postmortem examination of the brain. Rabies generally progresses quickly, so if undiagnosed neurological signs have not rapidly progressed within the first five days, rabies is most likely not the cause.

Risk factors

We see an increased incidence of rabies infections in horses and other livestock in the late summer and fall when wildlife populations peak. Horses contract rabies through the bite of an infected (rabid) animal, such as a raccoon, fox, skunk or bat. A horse’s curiosity can get the best of him, with bites typically occurring on the horse’s face and muzzle or lower limbs. Most exposures aren’t noticed and most bite wounds aren’t found. Since wildlife may enter barns (especially at night), both horses in stalls and those on pasture are at risk of exposure.

Due to the serious threat for human exposure when handling a horse with rabies, any suspected case of equine rabies should be handled as if it were positive until proven otherwise. You may become infected with the rabies virus through contact with saliva or brain/nervous system tissue from a rabid animal. Individuals who have been in contact with a horse since the onset of clinical signs should immediately consult with their physician regarding medical treatment.

Prevention is critical

Few diseases are more feared than rabies, and for good reason. One of the scariest things about the disease is that it is one of the hardest to recognize in horses. And while the odds are low your horse will get rabies, the odds are virtually zero that he will recover if he contracts the disease.

The importance of vaccination of companion animals, including horses, against rabies cannot be overemphasized. Fortunately, safe and highly effective vaccines are available, including EquiRab®, the only rabies vaccine designed, developed and labeled specifically for horses.

Talk to your veterinarian today to ensure your horse is up-to-date on rabies vaccination. For more information, visit www.getvaccinatingright.com.

[1] Equine Disease Communication Center (equinediseasecc.org)

[2] AAEP Core Vaccination Guidelines (www.aaep.org)

Copyright © 2017 Intervet Inc., d/b/a Merck Animal Health, a subsidiary of Merck & Co., Inc.

What did you think of this article?

Thank you for your feedback!