Equine rabies: A preventable but deadly disease
June 18, 2012
While doing chores one evening, you notice that the horse that the kids ride is a little lame in the hind legs. You reason that he is getting on older in years, it’s more than likely arthritis. The kids used him at a play day several days ago and he probably hasn’t quite recovered from all the activity.
The next morning, he acts like he might have a touch of colic, but readily comes to feed and acts all right otherwise. You keep an eye on him all morning and he doesn’t get any worse, so you figure it was just a reaction to a change of hay.
Evening chores are interrupted when he chokes on his hay and is drooling. You think to yourself “What in the world can happen next?”. You reach in his mouth to see if there’s something stuck in his teeth, but find nothing. He’s breathing okay, but he is really having trouble swallowing, you decide to call the vet and see what is recommended. That’s when your world, your family’s and a lot of other people gets turned upside down.
All of the above symptoms are some of the many warning signs for rabies in equines. Those symptoms also include fever, uncoordinated movements like stumbling, staggering, knuckling over at the fetlock joints, dizziness and balance problems, either a more nervous, agitated behavior, being droopy or dull acting, skin twitches around the eyes, general trembling, head shaking, pressing of head against objects, circling, abdominal pain, neck stretching, dribbling urine, constipation, acting blind, biting at it’s own legs and sides, and a stiff or limp tail.
Many of these symptoms are also found in other equine diseases, such as West Nile virus, equine protozoal myelocencephalitis (EPM), and tying up syndrome. This confusion as to the cause can lead to not only misdiagnosis but exposure to the deadly rabies virus.
Rabies is most commonly found in wildlife. Most often in skunks, raccoons, bats, fox and coyotes, though any warm blooded animal can get it. It has a long incubation period after exposure, with onset ranging from two weeks to several months. Once affected, there is no treatment and euthanasia is necessary.
The disease is carried in the saliva of the infected animal. Bites are the most common route of infection, though any break in the skin can be the entry point. The mucous membranes are also susceptible. For example, if the horses tosses it’s head or blows it’s nose, the saliva that gets in the air can land in the eyes or be breathed in through the nose or mouth.
It’s important to remember this any time a horse is acting “off” and is being handled for diagnosis or care. Latex gloves, protective eye wear and a face mask would be ideal attire, as well as long sleeves. Typically horse owners don’t even think about it being such a serious issue and are exposed before they know there is a danger.
Horses are less likely to have the “furious” type of rabies, meaning the classic frothing mouth, aggressive acting and attacking behavior most people would equate with rabies. However, they get the more subtle version most of the time, thereby making it a silent threat.
Rabies incubates at the wound site, then the virus moves into the central nervous system of the infected animal through the nerves. The distance between the point of entry of the virus and the brain determine how long there is before symptoms develop. For example, a horse that was bitten on the nose will usually show symptoms within weeks, whereas a bite on a hind foot could possibly take months to travel through the nervous system.
There is no test for rabies except for analysis of brain tissue. If an animal is acting strange or is suspected of biting something, care should be taken when euthanization occurs, so that the brain tissue is not damaged. That animal’s brain tissue is then sent to a laboratory for testing. Once a positive test is determined, it is then necessary to decide the level of risk, the infected animal posed on it’s victim. The victim can then be quarantined effectively to see if the virus develops, and if local regulations allow it.
Humans that are exposed to the virus can go through a vaccination protocol that involves multiple injections over a period of two weeks, The shots will cost in the range of $2000-2500, plus the cost of administration of the shots. Humans, when vaccinated this way, can be effectively treated and not get the disease.
People in the animal health field, such as veterinarians, veterinary technicians, animal shelter personnel and animal control officers are generally vaccinated against the virus as a preventative measure, but this isn’t a realistic option for the general public.
Prevention is still the most effective medicine against rabies. Pets have been vaccinated against rabies for years, and livestock can be too. Horses can be vaccinated very inexpensively, with a veterinarian administering the shot for around $12-20, depending on where you live. A licensed veterinarian keeps detailed records on the vaccination of the animal, and can help with verification in the event of someone trying to diagnose an illness in the horse, or when someone has been bitten.
The vaccine can also be purchased very reasonably and administered by the owner however, some states don’t allow this. It is also more difficult to verify a vaccination in the case of exposure when done by the owner.
The vaccine is very safe for the horse, though some muscle soreness at the injection site is common. Some may experience a small amount of swelling at the site, but it passes in a short amount of time.
In the opening scene of this story, this horse owner exposed him/herself, the children and anyone else who came in contact with this horse or it’s saliva in the days before showing symptoms. Vaccination is the only way to prevent rabies, and the best way to ensure that everyone around a horse is kept safe from exposure.
Though the incidence of rabies is relatively low in horses, one has to balance that with the dire consequences of a rabies diagnosis and the heart wrenching decisions and expensive treatments that follow. A “better to be safe than sorry” approach is best. F