Rabies

Disease Overview

Rabies is a rare but fatal viral disease that attacks a horse’s neurologic system and can be transmitted to people and other animals.

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The only monovalent rabies vaccine specifically for horses.

Transmission

Exposure occurs primarily through the bite of an infected animal, usually a raccoon, fox, skunk, bat or other wildlife source. Rabies is endemic in every state in the United States except Hawaii. Bites to horses occur most often on the muzzle, face and lower limbs.

Although rare, the virus can also be transmitted through open wounds, cuts in the skin, abrasions, direct contact with the mucous membranes (mouth or eyes) of infected animals, and aerosolization of nerve or central nervous system tissues during necropsy.

Clinical signs

While highly variable, clinical signs may include:

  • Fever
  • Lack of appetite
  • Blindness
  • Dysphagia
  • Hyperesthesia—manifests as self-mutilation
  • Muscle twitching
  • Lameness
  • Weakness and/or incoordination
  • Incontinence
  • Paralysis—ascending
  • Sudden death

Rabies in horses can take two forms: dumb and furious. In the dumb form, behavioral signs include depression or stupor. The furious form produces mania; these horses are extremely dangerous.

Risk Factors

  • 24-hour access to pasture
  • Living in an endemic area

References

“Rabies (Rhabdovirus),” AAEP Infectious Disease Guidelines, copyright 2017, aaep.org/sites/default/files/Guidelines/Rabies_Final.pdf.

“Rabies,” American Association of Equine Practitioners, copyright 2020, aaep.org/guidelines/vaccination-guidelines/core-vaccination-guidelines/rabies.

“Rabies,” Equine Disease Communication Center Disease Factsheet, accessed July 15, 2021,  aaep.org/sites/default/files/Documents/Outside%20Linked%20Documents/DiseaseFactsheet-Rabies%20Cobranded.pdf.