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Tetanus
in Farm Animals
Michael D. Piontkowski,
DVM
Senior Staff Veterinarian
Technical Service
INTRODUCTION
Tetanus is a profoundly fatal disease in domestic farm
animals, with worldwide distribution.
There is a wide variation in susceptibility to the
disease with horses and pigs being highly susceptible and
cattle, sheep and goats being less susceptible.
The organism that causes the disease, Clostridium
tetani, requires an anaerobic environment (no oxygen) in
which to grow. Animals
are at greatest risk of infection, due to growth
characteristics of the organism, when the bacteria enter an
area of the body without exposure to outside air.
Examples of these instances would include contamination
of deep penetrating wounds, post-castration and post-tail
docking (especially with banding procedures), umbilical
infections, severe skin lacerations and post-birthing uterine
infections. Once
the organism has entered the body under the right
circumstances, it releases an exotoxin that binds to certain
nerve fibers and results in muscle rigidity.
Clinical signs noted secondary to the muscle rigidity
include a “sawhorse appearance”, a fixed stare, erect
ears, a reluctance to eat or drink due to a “locked jaw”,
an elevated tail, flared nostrils and a protruding third
eyelid. Even with
treatment at this point, death is usually imminent.
CONTROL
AND PREVENTION
ACTIVE IMMUNIZATION
The best method of dealing with this disease, due to a poor
response to treatment, is
with an active immunization program.
An active immunization program involves vaccinating an
animal with tetanus toxoid (inactivated tetanus toxin) and
repeating this immunization in about 14 to 28 days.
Protection for that particular animal will be achieved
in about 7 to 14 days after the second injection and
protection lasts about a year.
Immunity achieved with this type of vaccination program
is due to the body recognizing the inactivated toxin in the
vaccine and certain white blood cells forming antibodies in
response. In
addition, the body will “remember” that particular vaccine
and be ready to respond quickly the next time it “sees”
the toxin again. Once
this type of immunity has been established in an animal, if an
animal is exposed to this disease, a booster injection of
tetanus toxoid will quickly reestablish protective immunity in
that particular animal. This
type of immunization program results in the best immunity
versus the disease, it is long lasting and can be used to
increase the amount of antibodies passed from the dam to her
offspring for protection to tetanus.
On the other hand, protection to tetanus is not
immediate and is not achieved until a short period of time
after the second injection.
PASSIVE IMMUNIZATION
An alternative to active immunization is passive immunization.
This involves administering antitoxin, which contains
antibodies to the tetanus toxin, to a susceptible animal.
This antitoxin is derived from the blood of horses that
have been actively vaccinated with tetanus solutions and
processed to contain high levels of antibodies to this
particular disease. Administration
of tetanus antitoxin to a susceptible animal results in
immediate, short-term protection.
This protection lasts about 10 to 21 days, depending
upon the degree of disease exposure and the species of animal
in which it is used. Passive
immunization protection is recommended for animals that have
not been vaccinated with tetanus toxoid or the animal’s
vaccination history is unknown, and the animal is exposed to
the disease situation or will be shortly.
Examples of these situations would be a deep
penetrating wound in an unvaccinated animal or an animal in
which the vaccination history is unknown, tail-docking and
castration of newborn lambs and umbilical infections. These
situations would not allow enough time for active immunization
to be established prior to disease occurrence.
This type of immunization program results in short term
protection and the fact that the product is derived from horse
blood, can result in allergic reactions in a small percentage
of animals post-administration.
Colorado Serum Company proudly
produces and distributes both forms of tetanus protection for
the livestock owner. Contact
your local distributor and request these and other fine
products from Colorado Serum Company
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