A comprehensive list of all the vaccinations
available for horses is listed below in the order of importance for the Greater Louisville
Region. This list also can apply to anywhere in the United States,
however, some regional variations exist, Potomac Horse Fever and Botulism
both being examples.
Tetanus: Of all the vaccinations that
horses receive, tetanus toxoid is by far the most important. Horses are particularly susceptible to the paralyzing toxin produced by the bacterium
Clostridium tenani in a wound. In addition, areas where horses are located
have high levels of the bacterial spores. Vaccination is highly efficacious in
preventing the disease. Foals should be first inoculated with tetanus toxoid at 4
months of age with a booster 3-4 weeks later. After that, annual boosters are
recommended. (Note: Tetanus Anti-toxin, often given at birth, does not invoke
long term immunity.)
Equine Encephalomyelitis: Also called
sleeping sickness, this highly fatal neurologic disease is carried by insect vectors.
While the incidence of disease is not common in this region, vaccines routinely
have both the Western and Eastern strains combined with other diseases. (Venezuelan
Encephalomyelitis is currently not in the United States, although it may be just south of
the border.) The vaccination schedule is the same as tetanus toxoid, and is
typically given at the same time.
(Recently, there has been a watchful eye being placed on
the spread of EEE. Outbreaks have occurred in South Carolina and other
It is not reported to be in Kentucky, but the situation is being monitored.
Those horses that have been vaccinated for tetanus by Häst need not worry, as both
Eastern and Western Equine Encephalitis have always been included with the tetanus
Rabies: The incidence of rabies in horses
in Kentucky varies from 2-6 cases per year. This disease is always fatal and has a
high level of public significance as human exposure can be devastating. The primary
carriers of rabies in Kentucky are skunks and raccoons. But even horses housed in
the city are not necessarily protected as two racing standardbred horses were diagnosed
with the disease a number of years ago. Foals may be vaccinated at 4 months of age
with a booster 3-4 weeks later. Annual boosters are recommended. Vaccination
of pregnant mares is not recommended as safety studies have not been performed.
West Nile Virus: The West Nile Virus has
made its way into the Kentucky and Indiana region late in the summer of 2001. It
affects a number of different species, including man, horses, and birds. It is only
spread by the bite of mosquitoes, so there is no direct horse to horse or horse to man
transmission. Although it is rarely fatal in humans, mortality rates in horses can
reach up to 40 percent. Even though the winter will kill the present population of
mosquitoes, the disease can remain endemic in an area. Early vaccination, before
there is a wide outbreak, is recommended. The vaccination is given initially with a
booster 3-6 weeks later, and then annually thereafter. (Note: The ability to
export a horse to another country may be adversely affected due to the patients new
Early signs of the disease can include muscle twitching in the
nose. If this is seen in your horse, it would probably be very wise to begin
treatment early. Once the disease has progressed to paralysis, the prognosis is very
Please have your horses properly vaccinated!
This consists of an initial vaccination, followed by a booster in 3-6 weeks. If
your horse has not had this vaccination protocol, he may be at risk. On a rare
occasion, even horses that have been vaccinated might become infected. This should
not deter consideration of vaccination. Your horse will be in a much better
position to fight West Nile if he has been properly immunized.
Strangles: This upper respiratory
disease, caused by Streptococcus equi, is highly contagious when present on a
farm. The disease is characterized by large abscesses under the throat which can
sometimes take weeks or months to resolve. Foals may be vaccinated at 2-3 months
with a booster 2-3 weeks later. Annual vaccination thereafter is recommended.
The newer intra-nasal vaccine is preferred over the previously available intramuscular
Equine Influenza: This respiratory
disease can often affect large numbers of horses, but is usually not fatal. The
immune response generated by the vaccine in the horse can be limited, especially in foals
where maternal antibodies from the mare may interfere with the development of immunity.
Even though vaccination can not insure that a horses will not contract the disease,
it can often be noted that horses do not seem to get nearly as sick when a vaccination
schedule assists in the immune process. With vaccination of foals demonstrating very
limited efficacy, the first dose may be administered when the horse is older than 12
months. Adults may be vaccinated at the rate of 1-4 times per year depending upon
the horses age and the risk factors of the environment and the density of the horse
population surrounding the horse in question.
Equine Rhinopneumonitis: Caused by a
herpesvirus (similar to the human common cold), this disease, like influenza, is rarely
fatal, but can cause the horse to be very sick for a prolonged period of time. And
like influenza, vaccination cannot guarantee that the horse will not contract the disease.
However, horses that have been vaccinated most often demonstrate much milder
symptoms that those that have not been vaccinated. Vaccination of foals is usually
done at greater than six months of age with 2-3 boosters 3-4 weeks apart. Adults
should be vaccinated 1-4 times per year depending upon risk factors.
EPM Vaccination: Although the
incidence of EPM is not high in the population of horses, those horses affected are often
severely affected with debilitating neurologic deficits. The vaccine has been
demonstrated to produce high levels of antibodies against the Protozoa Sarcocystis
neurona. In vitro tests have shown that the antibodies produced have been
effective against the organism. Challenge studies, however, have been difficult to
perform due to the nature of the disease process itself. A high degree of safety has
been demonstrated. No vaccination protocol for foals has been suggested, however,
Häst recommends that foals 4 months or over be vaccinated with a booster 4 weeks later.
Annual revaccination is recommended.
Botulism: This neurologic
disease, causing a flaccid paralysis, is often the result of horses eating
around the carcasses of animals that have died. It has also been cited
as being found in newly disturbed earth and in alfalfa hay. Häst has
known of five cases in the Louisville region over the past 20 years.
Many more cases have been observed in the Lexington area. Foals over 6 months
may be vaccinated. The protocol is three doses at four week intervals with an annual
Potomac Horse Fever: This disease,
which causes severe diarrhea and death, is not currently in this region. However,
horses planning to travel to the east coast, or other areas where the disease is
prevalent, should be vaccinated. Foals may be vaccinated at 4-6 months of age with 2
doses 3-4 weeks apart. Boosters may be given twice a year for those horses in an
Equine Viral Arteritis: Currently,
only certain breeding stock is being routinely vaccinated under specific state
regulations. These regulations should be strictly adhered to or the horse may face
serious obstacles to a breeding career.
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