Page 76 - January 2016 Speedhorse

RABIES IN H
by Heather Smith Thomas
Rabies is a very spo- radic disease, but one of the most feared
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Signs of rabies are varied and not always clear, and people may try to treat the animal for something else.
because it can occur in all
warm-blooded animals
and is almost always fatal.
There have been, how-
ever, a rare few that have
survived. Rabies is caused
by a virus that affects the
nervous system and is
transmitted by the saliva of
an infected animal—usu-
ally via a bite or by saliva
coming into contact with
mucous membranes (such
as the eye) or an opening
in the skin. This is an uncommon disease in horses and cattle, but occurs occasionally in these species when wildlife cases increase with more opportunities for exposure.
This disease goes in cycles in wildlife populations. Skunks, raccoons, canines (fox, coyote, wolves, dogs) and bats are the primary animals that spread rabies. Rabid skunks can be a risk for pets, humans, or for horses and livestock if skunks are wandering through a pasture or barnyard. Skunks are generally noctur- nal, so if you see a skunk wandering around during the day—especially if it is acting strangely—you might be suspicious that it could have rabies.
Be aware of animal behavior. If any animal is acting out of character, this is a clue that something is wrong. A wild animal may become bold and approach you instead of running away. A domestic animal that normally is very tame may suddenly become skittish and nervous. Others that are normally unafraid or aggressive may become shy. A barn cat that is normally shy and fearful, that would typically run out the back door of the barn or hide behind the hay when a human enters, may suddenly become friendly.
During an outbreak of rabies, we may see high numbers of wildlife cases in certain regions, and then numbers drop in subsequent years because there is a die-off of animals. Eventually, the number of cases comes back up again. Veterinarians recommend that all horse owners vaccinate their horses against rabies. It’s an inexpensive vaccine, and good insurance, espe- cially since this is a zoonotic disease and you could get it from a horse.
Amy Johnson, DVM, DACVIM, Large
Animal Internal Medicine, New Bolton Center in Pennsylvania, has treated a few horses for rabies. “In this area, it’s raccoon rabies. The last horse I treated was a retired racehorse. Around here, rabies is not one of the mandated vaccinations for horses at the track,” she says.
Racehorses are vaccinated against influenza, herpes and some of the other viral diseases, but some trainers don’t vaccinate against rabies because the risk for exposure is low since the horses are in stalls rather than out in a pasture where they might encounter wild animals, dogs or feral cats.
“This retired racehorse went to a rescue facility where he was vaccinated for just about everything— including botulism, West Nile, EEE, WEE, tetanus, etc.—except rabies. He was then adopted to a new home with a nice family. They had already vaccinated all their other horses for rabies and other diseases that spring and were told that this horse had already been vaccinated for everything. They assumed that this included rabies,” says Johnson.
“It was a lovely dairy farm where he was out in
a big pasture. Within a few months, he apparently encountered a raccoon and developed rabies. He was referred to us with a history of having been abnormal for several days. The farmer, his wife, daughter and
Amy Johnson, DVM, DACVIM, Large Animal Internal Medicine, New Bolton Center in Pennsylvania
As of 2010, rabies vaccination is now considered by the AAEP to be one of the core vaccines that should be required for all horses.
74 SPEEDHORSE, January 2016
EQUINE HEALTH