Click on the blue hyperlink above to learn more about BSE from the FDA.
January 27, 2004
Are cats at risk of getting Mad Cow Disease?
The following question and answer about Feline Spongiform Encephalopathy
was provided by Dr. James Richards and approved for distribution to members of AAFP.
Dr. Richards is the Director of the Cornell Feline Health Center and
the current President of the American Association of Feline Practitioners (AAFP).
The following comments should help alleviate fears
about your pet acquiring Mad Cow Disease from pet food.
"Q: I've been following the recent mad cow disease situation in Washington State
and I feel pretty confident that the government has safeguards in place to prevent
it from causing any problems. But I have a friend from Great Britain who told
me about cats getting sick from eating contaminated food during the mad cow disease
crisis over there, and now I'm a little worried. Are my cats now at risk of getting
"mad cat disease?"
A: You'd have to have been on the spaceship to Mars to miss hearing about mad
cow disease--more precisely bovine spongiform encephalopathy or BSE--found this
past December in a cow from Washington. The United States Department of Agriculture
(USDA) and the Food and Drug Administration (FDA) are working closely together
with state officials in the investigation, and if you'd like to stay informed,
I suggest you periodically check the website:
http://www.fda.gov/AnimalVeterinary/ResourcesforYou/AnimalHealthLiteracy/ucm136222.htm
The website contains a wealth of information and is constantly updated.
USDA, charged with assuring animal health
as well as the safety of certain meat and poultry products,
is leading the investigation of this BSE case,
whereas FDA's primary responsibility involves animal feed including cattle and cat food.
BSE is the bovine form of a rather mysterious family of contagious brain disorders
called transmissible spongiform encephalopathies or TSE's.
Recognized hundreds of years ago, it was only recently that
transmissible (capable of passing from one individual to another)
spongiform (looks like a sponge) encephalopathies (brain diseases)
were found to be caused by misshapen proteins called prions.
Like the proverbial bad apple spoiling the barrel,
prions coerce neighbor proteins in the brain to become malformed,
too, and it's this accumulation of dysfunctional proteins that causes the disease.
See the article entitled, "Prions: Puzzling Infectious Proteins," at the National Institutes of Health site,
http://science.education.nih.gov/home2.nsf/Educational+ResourcesResource+FormatsOnline+Resources+High+School/D07612181A4E785B85256CCD0064857B
Prions aren't alive in any sense of the word, and they're resistant to forms
of sterilization that inactivate infectious agents like viruses, bacteria, and fungi.
Prions escape the normal high-temperature rendering process used to transform
otherwise inedible tissues into meat-and-bone meal, a common constituent of cattle feed.
The BSE outbreak that peaked in the 1990's in Great Britain is believed
to have intensified through feeding cows meat-and-bone meal made, unknowingly,
from TSE-infected ruminant tissue. Feeding ruminant source products to cattle
has since been banned in Britain, so outbreaks like that shouldn't happen there again.
Similar stringent requirements are in place in the United States:
the FDA prohibits the feeding of ruminant-derived proteins to cows,
and the USDA restricts importation of live ruminants or ruminant products from countries
where BSE has been found. Both agencies are working diligently out of
"an abundance of caution" to prevent prions from entering either ruminant or human food products.
Not just cows
It would be bad enough if only ruminants like cattle, sheep, and goats were affected,
but TSE's occur in many other mammals including cats (dogs, pigs, and horses
appear to be resistant to infection). A human TSE variant called Creutzfeldt-Jacob
Disease (vCJD) is believed to be caused by eating contaminated beef products
from BSE-affected cattle. This disease, of course, is the main reason behind
all the safeguards; to date, there have been over one hundred confirmed and probable
cases of vCJD worldwide among the hundreds of thousands of people that may have
consumed BSE-contaminated beef products during the peak of mad cow disease in
Europe. The only reported case of vCJD in the United States is in a person who
contracted the disease while residing in the UK.
Feline spongiform encephalopathy, or FSE, is the cat form of the disease,
and upwards of 100 cases have been reported in Great Britain and Europe,
mostly during the BSE peak in the early to mid 1990's.
British cats were believed to have gotten the disease by eating
BSE-contaminated commercial cat food and butcher scraps,
and the number of new cases in domestic cats plunged once measures to prevent
BSE materials from entering the food chain were put into place; none has been
reported since 1999. No cases in US cats have ever been reported.
Could it happen here?
Our growing understanding of TSE's is helping regulatory agencies expand the
measures being taken to prevent BSE from ever becoming widespread in cattle here
in the States. The regulation of what can or cannot be included in meat products
approved for human consumption is an additional line of defense to protect people.
But according to the FDA, products not approved for human consumption, and rendered
products prohibited from cattle feed, are allowable for use in pet food. Nonetheless,
such products must originate from countries free of BSE. (The FDA reports that
none of the meat from the BSE-infected cow in Washington was released into distribution,
so none of it could have wound up in pet food. Interestingly, some pet food manufacturers
use only products approved for human consumption anyway.) As a further level
of protection to cats, the FDA disallows importation into the US of any pet foods
containing products derived from mammalian sources. So unless BSE were to become
prevalent in cattle in the US, the risk of BSE-contaminated pet food is very
small indeed. "
Dr. James Richards- Director, Cornell Feline Health Center
Cornell University College of Veterinary Medicine
Ithaca, NY 14853
January 11, 2004
AVMA update on BSE
Washington Cow with BSE Likely to Be Only Infected Animal in Herd: DeHaven (courtesy AVMA)
Since bovine spongiform encephalopathy was diagnosed in Washington state in December, the Department of Agriculture has been "operating out of an abundance of caution" with regard to public and animal safety, said Dr. Ron DeHaven, the USDA's chief veterinary officer. On Jan. 11, Dr. DeHaven spoke at the AVMA Veterinary Leadership Conference in Chicago about the ongoing epidemiologic investigation occurring on both sides of the U.S.- Canadian border.
"We know that even in countries with a high prevalence of the disease, most notably the United Kingdom, it is very rare for there to be more than one or two, or maybe three positive animals in a given herd," Dr. DeHaven said. "It's very likely that this (Washington state cow) was the only animal in that herd that was infected." Nonetheless, since the Holstein tested positive for BSE on Dec. 23, the USDA has traced, quarantined, and culled hundreds of at-risk cattle, recalled thousands of pounds of beef, and implemented several measures to ensure the safety of the food supply.
Dr. DeHaven believes one of the more important safeguards announced by Agriculture Secretary Ann M. Veneman is a national animal identification system. Because BSE is not a contagious disease, agriculture officials have had weeks to track down animals of concern. "But if we were dealing with a highly infectious disease, such as foot-and-mouth disease," he said, "we would need to be able to trace animals in a matter of hours if we had any hope of containing and eradicating this disease." Such an identification system has been in the works for more than two years. Dr. DeHaven hopes that resources will now be made available to accelerate the system's implementation.
The investigation has traced the infected cow to her birth herd on a dairy farm in Alberta, Canada, meaning there has not been a native-born case of BSE in the United States. Consumer confidence in the safety of U.S. beef remains high, and cattle prices appear to be rebounding. Dr. DeHaven referred to a study by the Harvard Center for Risk Analysis that concluded that if BSE is in the United States, then it exists at low prevalence. Moreover, the ban on ruminant-to-ruminant feed would eliminate the disease, even if the compliance rate were only 70 percent. The Food and Drug Administration claims a better than 99 percent compliance rate, Dr. DeHaven noted.
Many have tried comparing the BSE situation in North America with those in some European Union nations and Japan. "In fact, the situations are very much different," Dr. DeHaven said. There has been a high prevalence of the disease in some E.U. countries. Yet, extensive surveillance programs in Canada and the United States demonstrated a low prevalence of the disease here. Consumer confidence in the E.U. nations and Japan is so low that governments have gone to such extremes as testing animals that aren't of the susceptible population, such as cows younger than 30 months of age.
The United States is being pressured to follow those models, despite what is scientifically known about BSE, Dr. DeHaven noted. Trade has suffered a massive blow. In 2002, America exported $3.1 billion in beef and beef products. "Indeed, virtually all of that export market has now been shut off," he said, adding that Congress is likely to introduce any number of bills pertaining to the disease and its effects on trade.
