Vaccinations for sheep and goats
Vaccinations are an integral
part of a flock health management program. They provide cheap insurance against
diseases that commonly affect sheep and goats.
Probably, the only universally recommended vaccine for sheep and goats is
CD-T. CD-T toxoid provides three-way protection against enterotoxemia
(overeating disease) caused by Clostridium perfringins types
C and D and tetanus (lockjaw) caused by Clostridium tetani. Seven and 8-way combination
vaccines for additional clostridial diseases such as blackleg and malignant
edema are available, but generally not necessary for small ruminants.
Enterotoxemia type C, also called hemorrhagic enteritis or "bloody scours," mostly affects lambs and kids during their first few weeks of life, causing a bloody infection of the small intestine. It is oftenrelated to indigestion and is predisposed by a change in feed, such as beginning creep feeding or a sudden increase in milk supply.
Enterotoxemia type D, also called "pulpy kidney disease," usually affects lambs and kids over one month of age, generally the largest, fastest growing lambs/kids in the flock. It is precipitated by a sudden change in feed that causes the organism, which is already present in the young animal's gut to proliferate, resulting in a toxic reaction. Type D is most commonly observed in animals that are consuming high concentrate diets, but can also occur in lambs/kids nursing heavy milking dams.
To confer passive immunity to lambs and kids through the colostrum, ewes and does should be vaccinated 2 to 4 weeks prior to parturition. Females giving birth for the first time should be vaccinated twice in late pregnancy, about four weeks apart.
Maternal
antibodies will protect lambs and kids for about two months, if offspring
have ingested adequate colostrum. Lambs/kids should receive their first CD-T
vaccination when they are 6 to 8 weeks old, followed by a booster 2 to 4 weeks
later. If pastured animals are later placed in a feed lot for concentrate
feeding, producers should consider re-vaccinating them for enterotoxemia type
D.
Lambs and kids whose dams were not vaccinated for C and D can be vaccinated
with some success at two to three days of age and again in two weeks. However,
later vaccinations will be more successful since colostral antibodies interfere
with vaccinations at very young ages.
A better alternative may be to vaccinate
offspring from non-vaccinated dams at 1 to 3 weeks, with a booster 3 to 4
weeks later. Anti-toxins can provide immediate short-term immunity if dams
were not vaccinated or in the event of disease outbreak or vaccine failure.
Lambs and kids whose dams were not vaccinated for tetanus should be given
the tetanus anti-toxin at the time of docking, castrating, and disbudding,
especially if elastrator bands are used. Rams and bucks should be boostered
annually with CD-T.
In addition to CD-T, there are other vaccines that sheep and goat producers
may include in the flock vaccination program, depending upon the health status
of their flock and the diseases prevalent in their area.
Soremouth
There is a vaccine for sore
mouth (contagious ecthyma, orf), a viral skin disease commonly affecting
sheep and goats. It is a live vaccine that causes sore mouth lesions at a
location (on the animal) and time of the producer’s choosing. Ewes
should be vaccinated well in advance of lambing. To use the vaccine, a woolless
area on the animal is scarified, and the re-hydrated vaccine is applied to
the spot with a brush or similar applicator. Ewes can be vaccinated inside
the ear or under the tail. Lambs can be vaccinated inside the thigh.
Because
the sore mouth vaccine is a "live" vaccine and sore mouth is highly
contagious to humans, care must be taken when applying the vaccine. Gloves
should be used. Flocks which are free from sore mouth should probably not
vaccinate because the vaccine will introduce the virus to the flock/premises.
Once soremouth vaccination is begun, it should be continued yearly.
Footrot
Foot rot (and foot scald) is one of the most ubiquitous diseases in the
sheep and goat industry. It causes considerable economic loss due to the costs
associated with treating it and the premature culling of affected animals.
There are two vaccines for foot rot and foot scald in sheep. Neither product
prevents the diseases from occurring, but when used in conjunction with other
management practices such as selection/culling, regular foot trimming, foot
soaking/bathing, etc., can help reduce infection levels. Foot rot vaccines
should be administered every 3 to 6 months and especially prior to anticipated
outbreaks of hoof problems (i.e. prior to the wet/rainy season).
Caseous
lymphadenitis
There is a vaccine for caseous
lymphadenitis (CLA, cheesy gland, abscesses) in sheep. CLA affects primarily
the lymphatic system and results in the formation of abscesses in the lymph
nodes. It is highly contagious. When it affects the internal organs, it becomes
in a chronic wasting disease. The cost of CLA to the sheep and goat industry
is probably grossly underestimated. The CLA vaccine is convenient to use because
it is combined with CD-T. The CLA vaccine should only be used in flocks which
do not already show signs of CLA infection.
Abortion
Abortion is when a female loses her offspring during pregnancy or gives birth
to weak or deformed babies. There are vaccines (individual and combination)
for several of the agents that cause abortion in sheep: enzootic (EAE, Chlamydia sp.) and vibriosis (Campylobacter
fetus). Abortion vaccines should be administered prior to breeding.
Risk factors for abortion include an open flock and a history of abortions in the flock. Unfortunately, there is no vaccine (available in the U.S.) for toxoplasmosis, another common cause of abortion in sheep. Since the disease-causing organism is carried by domestic cats, the best protection is to control the farm's cat population by spaying/neutering and keeping cats from contaminating feed sources.
Rabies
Though the risk to sheep
and goats is usually minimal, rabies vaccination
may be considered if the flock is located in a rabies-infected area and livestock
have access to wooded areas or areas frequented by raccoons, skunks, foxes,
or other known carriers of rabies. Frequent interaction with livestock may
be another reason to consider vaccianting.
The cost of the rabies vaccine
relative to the value of the animals should be considered as well. The large
animal rabies vaccine is approved for use in sheep. No rabies vaccine is currently
licensed for goats. All dogs and cats on the farm should be routinely vaccinated
for rabies. Producers should consult their veterinarian regarding rabies vaccination.
In order for vaccination programs to be successful, label directions must
be carefully followed and vaccines need to be stored, handled, and administered
properly. Only healthy livestock should be vaccinated. It is also important
to note that vaccines have limitations and that the immunity imparted by vaccines
can sometimes by inadequate or overwhelmed by disease challenge.
With the increasing role of small ruminants in small farms and sustainable
farming systems and the rapid growth of the meat goat industry, hopefully
animal health companies will develop and license more vaccines for sheep and
especially goats. Scientists are currently working on vaccines to protect
small ruminants against worms.
Copyright © 2004.
Resources and additional reading
Understanding vaccination programs (timing is everything) - by Joe Rook
The use of vaccines in sheep - University of Minnesota
Vaccination schedules to raise antibody concentrations . . . - Cornell University
Created or last updated
by Susan Schoenian on
23-Dec-2009
.