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CLA
in Goats
Randall J Berrier ,DVM
Staff Veterinarian
Technical Service
Colorado Serum Company often gets a lot of
correspondence regarding caseous lymphadenitis (CLA) in goats
and questions about using our CLA vaccines (Case-Bac and
Caseous D-T) in goats. There
seems to be a lot of interest and misleading information
regarding vaccinating goats against CLA.
For more detailed information about CLA, the disease,
please refer to our vet's corner from June 2001, (volume 1 -
no.4).
Caseous lymphadenitis is caused by the
bacterial organism Corynebacterium pseudotuberculosis.
The two vaccines that Colorado Serum Company makes for
CLA are licensed for use in sheep only.
These two vaccines are also the only two commercially
available vaccines for combating CLA in the United States.
The vaccine (Case-Bac) is a combination bacterin/toxoid,
while Caseous D-T also contains tetanus toxoid and Clostridium
perfringens type D toxoid as well.
The main reason why Colorado Serum Company
did not have a label for usage of these vaccines in goats is
safety. Colorado
Serum Company originally tested caseous vaccines in goats and
noted varying levels of injection site reactions that went
from no reactions to swellings about 14 inches in diameter.
There would be associated lameness post-vaccination
that would last anywhere from 1 to 30 days.
All of these reactions would be unacceptable to USDA
and therefore Colorado Serum Company never pursued a license
in goats. Since
Colorado Serum Company was unhappy with the safety profile of
these vaccines in goats, we never pursued any further efficacy
testing in goats. Over
the years Colorado Serum Company has also received numerous
calls from the field from people who have used this vaccine
off label in goats. A
fair percentage of vaccinated goats will develop a fever and
become lethargic for a period of days.
These goats will sometimes go off feed or have a
reduction of feed intake.
Milking does can have a decrease in milk production.
Vaccinating pregnant animals can increase the risk
factors. As in
sheep, vaccinating goats that already have CLA will do
absolutely no good and will only make the above-mentioned
reactions worse. So
you can see why we cannot recommend vaccinating goats with
these vaccines.
However, all hope is not lost.
There are other options for goat ranchers.
First of all, I would strongly recommend having any
suspect abscesses sampled by a veterinarian and submitted to a
veterinary diagnostic lab to confirm if your herd has
CLA. An article
by Gezon, Bither, Hanson and Thompson in the Journal of the
American Veterinary Medical Association 1991; 198:257-263,
reported that over a 16 year period Actionmyces pyogenes
was cultured 3 times more often than C. pseudotuberculosis in
a particular goat herd with an ongoing history of internal and
external abscesses. The
point is - not every abscess in goats is CLA!
If you confirm that you do indeed have CLA in your goat
herd I would recommend not treating goats that have abscesses
and either selling them or isolating them.
Since there is no commercially available vaccine
available for goats you may want to consider having an
autogenous vaccine made from a sample of one of the abscesses
that tested positive for CLA.
Most autogenous products are whole-cell bacterins.
It has been our experience that a bacterin/toxoid
provides a much better immune response.
I don't know how much protection goats are going to
receive from an autogenous bacterin.
You may want to try an autogenous caseous bacterin in a
limited number of goats and determine if it works in your goat
herd.
Hopefully this helped answer questions
about using Colorado Serum Company Case-Bac
and Caseous
D-T vaccines in goats and why Colorado Serum Company can't
recommend it. Currently,
Colorado Serum Company is actively pursuing a safer vaccine
for CLA that can be licensed for use in goats.
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