Agriculture Reference
In-Depth Information
Malignant Edema
A disease that results from a wound that's become infected by one of several
Clostridium
species, malignant edema is usually fatal. If a wound infected by
Clostridium
is caught early, antibiotics may be effective. Clostridia are environ-
mental bacteria that normally reside in soil and manure. The best approach
to infection with these bacteria is to keep wounds clean and maintain injured
animals in a clean environment —on a healthy grass pasture, for instance —
instead of in a manure-contaminated yard. Vaccines are available.
Pinkeye
Infectious keratitis, known commonly as pinkeye, is another infection caused
by a chlamydial organism. This disease can be quite contagious. Infected eyes
become red, infl amed, and watery; if the disease is allowed to progress, the
eyes become opaque and ulcerated, with blindness the eventual outcome.
Your veterinarian can supply an ointment or a powder to put in the eyes of
infected animals.
Scrapie
Scrapie, like mad cow disease (bovine spongiform encephalopathy), chronic
wasting disease in deer and elk, and Creutzfeldt-Jacob disease in humans,
is caused by something called a prion. Prions are abnormal subparticles of
a protein molecule. Of all the diseases discussed here, scrapie has been rec-
ognized for the longest period — almost 200 years — and it has been found
in North America since the 1940s. Despite the fact that the disease has been
around for so long, little is understood about the causative prions and how the
disease works. Because the science and understanding of prions is still fairly
new, there's obviously still lots to learn. Two things scientists now believe is
that there is a gene associated with it, and there appears to be an environmen-
tal factor associated with dietary metals (particularly a defi cit of copper and
excess manganese) involved in the disease's development. The best evidence
suggests that it does not pose a human health risk.
There are a slew of symptoms for scrapie, ranging from exaggerated
movements to weight loss, itching, and scraping and biting wool on the sides
and legs. There is no known cure, but there is a Voluntary Scrapie Flock
Certifi cation Program managed by the USDA's Animal and Plant Health
Inspection Service (APHIS). APHIS has information about the program at its
Web site (see Resources), plus a number of short videos that show what the
disease looks like. Purchase sheep from fl ocks enrolled in the program.
