Literally any mammal can become ill with rabies if exposed to the virus. Rabies is caused by a group of viruses known collectively as rhabdovirus. Most commonly dogs, skunks, raccoons, foxes and bats are diagnosed with rabies, but other animals such as cats, horses, goats, cows, sheep and even people can get the disease if bitten by a rabid animal. Rhabdovirus is considered to be zoonotic, which means it can be transferred between species and between animals and humans. Although it is highly unlikely a human could get rabies from a horse, inadvertent direct contact with the saliva under the right conditions could occur.
All horses that are diagnosed with rabies will die, typically in three to five days of the first sign of the disease. Since effective vaccines are available to prevent the horse from developing rabies should he or she be exposed, it is well worth the addition of the vaccine to the regular schedule.
Horses that develop the clinical symptoms of rabies will generally exhibit signs of low appetite, excessive salivation from the mouth, agitation and excitability, sensitivity to light, difficulty swallowing, lack of coordination, seizures and even aggression. Colic and signs of convulsions and paralysis will typically be noted within 24-48 hours of the milder clinical signs. Since the disease is always fatal most horses that are known to have exposed to rabies and are exhibiting the signs are humanely put down. Symptoms will usually come on very rapidly and horses should be immediately isolated and all materials used in treating the horse should be thoroughly disinfected after use. Bedding should be burned and programs to carefully disinfect boots, rakes, shovels, stalls and people in contact with the horse or the area the horse is housed should be immediately implemented.
Once a horse has been bitten by a rabid animal the development of the first signs will usually be in two to ten weeks. Diagnosis becomes more problematic if the bite is not noted or if the incubation of the rabies virus is longer than expected. In rare cases the time between the bite and the clinical signs can be up to one year, making a diagnosis very difficult. In addition to the time lag between the bite and the diagnosis a further problem is that the symptoms of rabies are very similar to relatively common conditions. These can include equine herpes virus, West Nile Virus and myeloenchephalitis. Unfortunately the only way that rabies is completely confirmed as a diagnosis is through a post-mortem examination. The carcass should be disposed of as required by the agricultural department in your area, usually under the supervision of the vet.
Foals as young as three months can be vaccinated for rabies. Knowing if rabies is a problem in your area and also monitoring the areas that you take your horse to is important. If you are planning on trailering or moving your horse to a new area contact a local vet to see if rabies has or is a problem and if vaccination is recommended in the area.