Agriculture Reference
In-Depth Information
sexually transmitted disease that is generally well under way before being
noticed during a physical examination.
Signs can include swelling of the epididymis (located at the base of the tes-
tis) and the presence of hard, lumpy tissue; these signs show that the disease
is far advanced. It is transmitted from one ram to another via the ewes during
breeding season. In some cases a ewe may become infected, resulting in abor-
tions, stillbirths, and weak lambs. As the disease, when caused by
B. ovis,
can
be passed to humans from consumption of unpasteurized milk and cheese, it
is particularly critical for sheep dairies to keep the infection out of their ani-
mals. (The only way to contract brucellosis from sheep is through consump-
tion of unpasteurized products; shepherds can handle milk or semen samples
for testing without concern, and pasteurized milk is safe.)
The good news is that there are several effective testing systems available,
with an ELISA being probably the most commonly used. Demand a negative
ELISA on any ram you're thinking of purchasing, and if you're purchasing
pregnant ewes or ewes that have recently given birth, ask for proof of nega-
tive ELISAs on that farm's rams! Ewes that have been dry for several months
have generally cleared any organisms from their systems. Accurate testing
within an existing fl ock also enables producers to identify diseased rams so
they can be readily culled. There is a vaccine available, but most veterinar-
ians are recommending that any rams that test positive be culled, as such a
program ultimately clears the disease from the fl ock.
Treatment is generally unsuccessful, but if caught early through testing,
when the only indication is the presence of white blood cells in the semen,
then high doses of antibiotics, such as tetracycline and streptomycin, may be
effective. Although this can be a way to save a valuable animal, it requires iso-
lation and extensive monitoring. Again, culling is usually the best approach
to prevent the spread of the disease.
Orchitis
Infl ammation of one or both of the testicles, known as orchitis, may be caused
by several species of bacteria (including
Brucella ovis
). If just one testicle is
affected, the ram can still reproduce after treatment with antibiotics (oxytet-
racycline and procaine penicillin are the two most commonly used), but if
both testicles are infected, he will be sterile. The symptoms are swelling, pain,
and heat in the affected testicle.
