Vaccination Chart At Bottom Of Page
What Is A
Vaccination involves the injection (with a sterile syringe and
needle) of bacteria or viruses that are inactivated or modified to
causing actual disease in the horse. Two or more doses are
usually needed to initiate an adequate immune response.
Once the immunization procedure is completed, the protective
antibodies in the blood stand guard against the invasion of specific
diseases. Over time, however, these antibodies gradually decline.
Therefore, a booster shot is needed at regular intervals. Protection
against some diseases such as tetanus and rabies can be
by boostering once a year. Others require more frequent
provide adequate protection.
Why The Need To Vaccinate?
It is up to you to protect your horse against contagious
diseases and parasites. Immunizations easily and effectively protect your
horse from the ravages of disease. Vaccinations place a protective
barrier between your horse and a whole list of problems: tetanus,
EPM, West Nile,
encephalomyelitis (sleeping sickness), influenza, rhinopneumonitis, rabies,
strangles and others.
A good immunization program is essential to responsible horse
ownership, but just as in humans, vaccination
does not guarantee
In some situations,
may decrease the severity of disease but not prevent it completely.
This is due
many complicated scientific reasons, such as differences in the
type or severity of some diseases
(such as influenza).
Vaccinations are also a vital part of proper equine management. If
used in a program that includes regular deworming,
of clean water, a good nutrition program, and a safe
environment, you and your equine will be all set to
productive years together.
Do You Need?
Equine Vet Service can help
you design and maintain a health management program to reduce exposure to
infectious disease agents
in your horse's environment and lessen the incidence of illness.
The specific immunizations needed by a particular horse or horses
depend upon several factors:
environment, age, use, exposure risk,
geographic location, and general management. We can help you determine
the vaccination program best suited to your horse's
The following diseases are those most often vaccinated against.
Your horse(s) may or may not need all of them.
Sometimes called "lockjaw," tetanus is caused by
toxin-producing bacteria present
in the intestinal tract of many
animals and found
in abundance in the soil where horses live. Its
can exist for years. Symptoms include muscle stiffness and rigidity,
hypersensitivity, the legs stiffly held in a locked position as the
disease progresses, muscles in the jaw and face stiffen, preventing
animal from eating or drinking. More than 80 percent of affected
horses die. Luckily, this disease is not
contagious. Contamination is
especially in the
case of lacerations and deep punctures.
The spores enter the body through
wounds, lacerations, or
the umbilicus of newborn foals.
particularly susceptible to the paralyzing toxin
produced by the bacterium
in a wound. In addition,
areas where horses are located have high levels of the
All horses should be immunized annually against tetanus. Additional
boosters for mares and foals may be recommended by your
veterinarian. Available vaccines are inexpensive, safe, and provide
Of all the vaccinations
that horses receive,
toxoid is by far the most important. The vaccination is highly efficacious in preventing the disease.
There is also a tetanus antitoxin that only offers protection for up
to three weeks,
and it has the potential to cause liver
More commonly known as "sleeping sickness," this
disease is caused by the
Western Equine Encephalomyelitis (WEE)
the Eastern version (EEE). WEE has been noted throughout
North America, while EEE appears in the east and southeast.
the Venezuelan variety, has not been seen in the
United States for
many years. However, a recent outbreak of VEE occurred
Sleeping sickness is most often transmitted by mosquitos, after the
insects have acquired the virus from birds and rodents.
are susceptible when bitten by an infected mosquito, but direct horse-to-horse or horse-to-human transmission is
Symptoms vary widely, but all result from the degeneration of the
brain. Early signs include fever, depression, and appetite loss.
Later, a horse might stagger when it walks, and paralysis develops
in later stages.
About 50 percent of horses infected with WEE die,
and the death rate is 70 to 90 percent of animals infected with EEE
All horses need an EEE and WEE vaccine at least annually. Pregnant
mares and foals may require additional vaccinations.
The best time
to vaccinate is spring, before the mosquitos become active.
The vaccination schedule is the
same as tetanus toxoid,
and is typically given at the same time.
South and West, some veterinarians choose to add a booster shot in
the fall to ensure
extra protection all year-round.
respiratory disease can often affect large numbers of horses, but is usually not
Influenza is one of the most common respiratory diseases in
The risk of influenza is
higher for young horses than older
horses. The virus is highly
contagious and can be transmitted by the air
from equine to equine over distances as far as 30 yards, for
example, by snorting or coughing.
Signs to watch for are similar to those in a human with a cold,
i.e., dry cough, nasal discharge, fever, depression, and loss of
With proper care, most equines recover in about 10 days.
Some, however, may show symptoms for weeks, especially if put back
work too soon.
Influenza is not only expensive to treat, but
results in a lot of "down time" and indirect financial loss, not to
discomfort to your equine.
Unfortunately, influenza viruses constantly change in an effort to
bypass the horse's immune defense. Therefore, duration of protection
is short-lived and revaccination is recommended.
Since the virus can mutate
frequently, vaccinations should contain the most recent
Not all equines need influenza vaccination. However, animals that
travel or are exposed to other equines should be regularly
|immunized against influenza. Follow your veterinarian's advice as to whether
your equine needs influenza vaccine.
Rotavirus causes diarrhea in foals anywhere between 12 hours of age to five
months of age.
The vaccine has some efficacy, therefore mares should be
vaccinated at eight, nine, and 10 months of gestation.
Foals can be
vaccinated at a young age.
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
will not contract the
disease. However, horses that have been
vaccinated most often demonstrate much milder symptoms that those
that have not
Two distinct viruses, equine herpesvirus type 1
(EHV-1) and equine herpesvirus type 4 (EHV-4),
cause two different
diseases, both of which are known as rhinopneumonitis. Both cause
respiratory tract problems,
and EHV-1 may also cause abortion, foal
death, and paralysis.
Infected horses may be feverish and lethargic,
and may lose appetite and experience nasal discharge and a cough.
Young equines suffer most from respiratory tract infections and may
develop pneumonia secondary to EHV-1.
Rhinopneumonitis is spread by aerosol and by direct contact with
secretions, utensils, or drinking water. Virus may be present
but unapparent in carrier animals.
All pregnant mares must be immunized. Foals, weanlings, yearlings,
and young equines under stress also should be vaccinated.
protection is short. Therefore, pregnant mares are vaccinated at
least during the 5th, 7th, and 9th months of gestation,
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.
respiratory disease, caused by Streptococcus equi, is highly contagious
when present on a farm. Horses could carry
organism in the guttural pouch for at least two years.
The disease is characterized by large abscesses under
the throat which
can sometimes take weeks or months to resolve.
There may be
some side effects associated with vaccination;
therefore, it is
discuss the risks versus benefits of
The Strangles vaccine is not a routine part of the
unless there is a problem
with strangles in the area.
This is due to a high
risk of local reaction and other side effects with the injectable vaccine.
does not provide
long-term immunity, and it should not be given
with other shots.
Foals may be
vaccinated at 2-3 months with a booster 2-3 weeks later.
Rabies is a frightening disease which is more common in some areas
than others. Equines are infected infrequently,
Rabies has a high level of public significance as human exposure can be
devastating. Rabies can be transmitted
to humans, although there are no
reported cases in humans from equine exposure. The rabies
vaccine is a “must-do.”
The primary carriers of rabies in Kentucky are skunks and
raccoons. But even horses housed in the city are not
as rabies can be carried by dogs, cats,
squirrels or any warm blooded mammal.
Foals may be vaccinated at 4 months of age with a booster 3-4 weeks
later. The rabies shot is given in two initial
followed by yearly boosters.
Vaccination of pregnant mares is not
recommended as safety studies have not been performed.
This disease is found mainly in the mid-Atlantic states, and vaccination
might not be indicated in your area.
Botulism can be fatal
and is very
expensive to treat. It causes a flaccid paralysis,
and is often the result of
around the carcasses
that have died. It has also been cited as being
found in newly disturbed
earth and in alfalfa hay.
Botulism is known as "shaker foal
syndrome" in young horses.
Botulism in adult horses,
poisoning," also can be fatal.
Foals are most commonly affected,
but horses of all ages
are at risk.
your veterinarian for his or her recommendations in your area.
Vaccines are not available for all
types of botulism, but
pregnant mares can be vaccinated in endemic
Equine Viral Arteritis
EVA is a contagious, sexually transmitted disease
that can cause abortion,
edema (fluid swelling), and various other symptoms.
It is a complicated disease which can result
in some breeding restrictions and
Vaccination is very effective and is
required annually by law for
Thoroughbred stallions in Kentucky,
including teasers. Mares sent to a positive stallion should be
Because the vaccine is a
modified live vaccine, it is possible
for a vaccinated animal to pass the disease on by respiratory
infection to other horses in close proximity for a period of
four weeks. Consequently, all horses in the same barn should be
vaccinated at the same time and quarantined for three to four weeks.
A blood test should be done
before the first vaccination to differentiate a positive result from
exposure vs. vaccination.
per year should be sufficient.Follow your
veterinarian's recommendations. Currently, only certain breeding stock is being routinely
specific state regulations.
These regulations should be strictly adhered to or
the horse may face serious obstacles
to a breeding career.
Potomac Horse Fever:
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 endemic area. One
third of affected horses die.
Contact your veterinarian
for further advice..
West Nile Virus:
The West Nile Virus affects a number of different species, including man, horses, and
birds. It is most commonly spread by the bite of
a mosquitoes, no direct horse
to horse or horse to man transmissions are known at this time. 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,
annually thereafter. In places with a mild winter boosters
could also be given in the fall.
EPM is a debilitating neurologic disease of horses.
It can affect the brain, brainstem,
spinal cord or any combination of these three
areas of the central
nervous system. The disease may present itself with
a variety of different clinical signs,
dependent on the location
of the damage caused by the organism
within the CNS.
incidence of EPM is
not high in the population of horses,
those horses affected are often severely affected. The causative agent of EPM has been
identified as Sarcocystis neurona.
Clinical signs are vague, but can include weakness, lameness,
incoordination, difficulty moving (especially in hindquarters), or in
from lying down.
Signs can also include seizures, weight loss, blindness, loss
of balance, head shaking and
Possum feces are
the source of the infection for horses. Possums acquire the
infection by eating infected birds. Horses are then
affected by eating pasture, hay, grain, or water contaminated with
has been demonstrated to produce high levels of antibodies against the Protozoa
In vitro tests
have shown that the antibodies
produced have been
effective against the organism. Foals 4 months or over
may be vaccinated and follow
with a booster 4 weeks later.
Annual revaccination is
Foals are born immunocompetent,
which means they have the ability for a normal
immune response. Therefore, if a mare is not vaccinated,
then a foal can be
at any time.
However, if a mare is vaccinated, then she can pass
along her antibodies in the colostrum
(first milk). Adequate colostrum
essential. Sometimes if
administered to foals too early they interfere with colostral
antibodies. Today, vaccine recommendations for
young horses have
each vaccine having a different timing for the
initial dosing series.
The schedule below is a
suggested vaccination schedule and is based on
generally accepted veterinary practices.
Infectious disease control programs in conjunction
with vaccinations are important in
maximizing the health, productivity
and performance of your horse.
Schedules for stallions should be consistent with the vaccination
of the adult horse population
on the farm and modified
according to risk.
You should consult with your veterinarian regarding a
vaccination program that will
provide the most benefits for your horse.
equine encephalomyelitis, WEE=western equine encephalomyelitis,
VEE=Venezuelan equine encephalomyelitis; EHV-1=equine herpes virus