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CAMPYLOBACTERIOSIS
in Ewes (Vibrionic Abortion)
Douglas A. Anderson,
DVM
Staff Veterinarian
Technical Service
One of the
major causes of ovine abortion is campylobacteriosis (formerly
vibriosis). Campylobactre
fetus subspecies fetus and Campylobactre jejuni
are the bacteria responsible for the disease.
They are small, motile, gram-negative rods that
normally require special microscopic techniques to confirm or
identify their presence.
Pregnant ewes
that become infected may lose weight and appear unthrifty.
Diarrhea may be present.
They usually abort late in their pregnancy.
They may also deliver stillborn or weak lambs.
In unvaccinated flocks, the abortion rate may reach 70%
of the ewes. The
aborted fetus is autolyzed (already showing signs of
decomposition). This
is in contrast to a fresh fetus in Chlamydial/Enzootic
Abortion of Ewes (EAE), which is another common cause of ovine
abortion. The
placenta is often hemorrhagic (bloody), necrotic
(decomposition), and edematous (swollen, leathery).
Following the abortion, the ewe may develop an
infection of the uterus (metritis) and require additional
medical attention. Mortality
in the ewes may exceed 5%.
Surviving ewes may become carriers.
This disease
is very contagious and spreads rapidly among the remaining
ewes unless very strict hygiene is practiced.
The fetus, placenta, birth fluids, vaginal discharge,
and feces from the ewe are all sources of infection.
If the water or feeding areas become contaminated with
these materials, the abortion rate can be very high.
Isolate the aborting ewes immediately and consult with
your veterinarian on recommended treatment, proper disposal of
the aborted fetus/placenta, and disinfection procedures.
The veterinarian may also want to perform a necropsy or
take samples for an accurate diagnosis.
Prevent the
disease from spreading by limiting access to the aborted
materials by wild birds and wild or domestic mammals, which
can carry the bacteria to other lots or ranches.
Provide feed in bunks off the ground to reduce fecal
contamination (a potential source of the bacteria).
Take measures to assure that the water supply and
drinking area does not become contaminated with feces, aborted
material, or vaginal discharges.
The use of separate boots, coveralls, and plenty of
disinfection is highly recommended and cannot be stressed
enough. Additionally,
these organisms are infectious for man and will cause a very
serious enteritis. Cleanliness
is absolutely essential.
This
disease can be controlled with the use of a vaccine like CAMPYLOBACTER
FETUS BACTERIN, Ovine Origin from Colorado Serum Company.
Vaccinate all incoming and unvaccinated ewes thirty
days prior to breeding season and again sixty to ninety days
later. Follow up
with a booster every year at the onset of breeding season.
While some immunity is obtained following an outbreak,
immunity against one strain of Campylobactre is not
cross-protective against the other strain.
This false sense of security combined with the presence
of carrier ewes can result in further abortion storms.
It is equally important to realize, that
campylobacteriosis tends to be cyclical.
Two to three good years might lull a rancher into
reducing his vaccination program, only to suffer abortion
losses as the next lambing season approaches.
Consult with your veterinarian for the program that
best fits your needs.
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