Veterinary Science Florida Agricultural
Mimeo Report VY66-2 Experiment Stations
June, 1966 Gainesville, Florida
A VACCINATION PROGRAM FOR HORSES1
Wayne W. Kirkham2
Vaccination is an attempt to get the highest level of immunity
in an animal and thus provide resistance to specific diseases. Such
a program is planned so that the animals will be immunized at a given
time to build resistance to specific seasonal diseases.
This resistance is dependent upon the presence of antibodies in
the circulating blood. There are two ways to get the antibodies into
the animal. First, they can be transferred from another animal. The
colostrum contains a high level of antibodies, therefore the dam
transfers antibodies to the young during the first few hours of life.
They can also be transferred in antiserum from hyperimmunized
animals to others. This is called passive immunity, because the
antibodies or resistance lasts only a short period of time.
Secondly, it is possible for vaccination and stimulation of the
formation of antibodies within their own body, active immunity. This
occurs during an infectious disease and in most instances the recover-
ed animal is relatively resistant to a second attack. It is also
possible to vaccinate an animal, resulting in the stimulation of anti-
body production. Duration of active immunity varies greatly, depending
upon the specific disease.
There are four main factors to consider when planning theequine
immunization program. First, it is necessary to know the disease for
which one wishes to build resistance. It is not satisfactory to say
that it is a vaccination for "respiratory disease." It must be a
vaccination for a specific respiratory disease such as equine
Secondly, it is essential to know the types of biological
products available for each disease and the results that can be ex-
pected. Constant improvement is being made in these immunization
Third, the duration of resistance varies with ep h sease.
Likewise, the type of product used will influence t n of
IPresented at the Fourth Annual Light Horse Shor Cours A June
1966, Gainesville, Florida. _
Kirkham, Associate Virologist, Department of Vete a'ocience.
Fourth, the type of operation being pursued will influence the
immunization program needed. This would include the number of horses
kept on a premise, geographic location of the operation, purpose for
which the animals are maintained and the value of the animals. As
the number of animals kept on a premise is increased, the need for an
immunization program is increased. Also, the more the animals are
moved to and from the premises, the greater the need for a vaccination
It is also important to consider the factors upon which a good
immunization program is dependent. There are three main factors
which influence the degree of immunity produced by vaccination;
product, administrator and the animal, each dependent upon the other.
In general, the products used for immunization of animals are
considered harmless to the animal for which it was intended. Most
products will give some degree of immunity when properly administered.
The manufacturers are continually improving the products, therefore
the recommendations for a given vaccine may change from one year to
the next. Second, the administrator or the person giving the vaccine
should secure the best product possible, properly store the vaccine,
read the directions carefully and then administer the vaccine as
recommended by the manufacturer. Third, the animal's health plays a
major role in the success of any immunization program. Animals under
six months of age frequently do not respond as well to a vaccine as
do older animals. Likewise, animals in poor condition, whether from
sickness, parasites or nutrition, do not build a high level of
immunity following vaccination.
A vaccination program for consideration is presented in Figure 1.
All horses should be immunized for tetanus and viral encephalitis.
The other diseases may or may not be included in the program. In
some instances it is advisable to immunize for other diseases. But
in all instances, visit with your veterinarian at least once a year
to plan an immunization program to get the best possible protection
for your horses.
AN EOUINE IMMUNIZATION PROGRAM TO CONSIDER
Consult Your Veterinarian for Further Information on Your Vaccination Schedule
Disease Product Procedure Precautions
For Eastern and
All animals 3 months or older,
2 doses, 4-8 weeks apart, with
3rd dose 6 months later, then
annually. Give before surgery
and after wounds and to pregnant
mares prior to foaling.
Give to newborn, and to unvacci-
nated animals at time of injury
or at surgery.
All animals 3 months or older.
Annual vaccination, 2 doses,
7-14 days apart, prior to
2 doses, 4-12 weeks apart.
3 doses, 7 days apart. Divide
each dose between 2 sites. One
"booster" dose annually after
immunization or infection.
"Planned Infection" 2 doses--
July and October. To all
equines on farm.
Not long lasting.
Not for foals under
Give only to healthy
animals. Do not use on
foals less than 3 months
old, on pregnant mares or
during infection. May
Make sure it is necessary
on your farm. Must have
a planned breeding program.
Mares should be less than
5 months pregnant. Do not
move horses for at least
*Requires a permit from the State Veterinarian.