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Aflatoxicosis
is discussed in the 1955 First Edition of the Merck Veterinary Manual
under the heading, "Moldy-Corn Toxicosis." At that time, it was
described as a hemorrhagic disease of swine and cattle that have ingested
moldy field corn. The disease was said to be caused by an unidentified
species of the fungus, Aspergillus, and a strain of Penicillium
rubrum, another fungus. The toxicosis was said to have been observed
mostly in the Southeast in parts of Alabama, Georgia, and Florida. The
toxin caused clinical and pathological symptoms in cattle, swine, and
mice. The producer often lost between 5 to 55% of the animals that had
ingested the moldy corn. The clinical symptoms caused severe damage to the
liver.
Fifty years
later, in 2005, the Ninth Edition of the Merck Veterinary Manual reports
that aflatoxins are produced by certain strains of Aspergillus flavus
and Aspergillus parasiticus on peanuts, soybeans, corn and other
cereal grains. It is possible for the fungus to exist on the grain and not
produce aflatoxin. The two things that are required are high moisture
content and constant day and night temperatures of greater than 70°
Fahrenheit. The toxic response and disease by mammals and poultry vary
greatly due to several factors. Some of these factors include species,
age, sex, nutritional status of the animal, and the level of aflatoxin
contamination in the feed. In addition to affecting a number of farm
animals such as poultry, pigs, pregnant sows, and calves, it also affects
dogs. Generally, adult cattle, sheep, and goats are relatively resistant
to the acute form of the disease in which death occurs in a short period
of time. Over longer periods, even the adults can be affected.
If you have
been paying attention to the news recently, you may be aware that Diamond
Pet Foods announced a voluntary recall of certain lots of their pet food.
Information abut the recall may be obtained at their website, www.diamondpet.com.
The recall was because of aflatoxin found in the food.
Mid-December
through Mid-January our Alabama Department of Agriculture and Industries
Veterinary Diagnostic Laboratory has had four cases in which dogs had died
of acute liver failure, which is consistent with aflatoxicosis. Of the
four premises represented in those cases, two were accompanied with
samples of dog food which tested positive for the presence of aflatoxin.
General clinical in dogs are dose dependent and include unthriftness,
weakness, anorexia, vomiting, diarrhea and sudden death.
Because of
the testing done on shipments of grain, aflatoxicosis is seen much less
often than it was years ago. Grain that is used commercially is tested for
the presence of aflatoxin; however, in a large shipment, there could be
one area where the toxin is located that is not tested. It may be like
finding a needle in a haystack.
According
to Dr. George D’Andrea, a toxicologist at our diagnostic laboratory, you
cannot look at corn and tell if aflatoxin is present or not. In his
experience, sometimes corn that has the most mold on it will test negative
for the toxin, while some corn that looks cleanest to the naked eye will
have a high level of contamination.
We are
fortunate to have the staff and personnel that we have at our veterinary
diagnostic laboratories in Alabama. They provide tremendous expertise to
the agriculture and companion animal community. We often think of their
importance in detecting foreign animal diseases such as Avian Influenza,
but they also provide a valuable service in helping the practicing
veterinarian diagnose diseases such as aflatoxicosis in pets.
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