Vaccinations for Sheep and Goat Flocks
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by Susan Schoenian
Area Agent, Sheep and Goat Specialist
Western Maryland Research & Education Center
Maryland Cooperative Extension
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Vaccinations
are an integral part of a flock health management
program. They provide cheap insurance against diseases
that commonly affect sheep and goats.
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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.
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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. |
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.
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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). |
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
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. |
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.
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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. |
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