FOOD FOR THOUGHT: Mad Cow and Wasting Disease
Have you been reading the papers, watching the national news or listening to talk radio? If so, chances are you've been exposed to the term Mad Cow Disease. First in Great Britain, then in Canada, and most recently a cow in Washington State, the scare – if not the actual disease – has spread. Recently, even a case in Goats has been confirmed in France! Can my dog get mad cow disease from kibble?
We know it is possible for a variant of Mad Cow Disease to be passed to humans through meat consumption. What about our pets? Are they also in danger?
Whether feeding a premium brand kibble, or hypoallergenic proteins of venison or elk, dog owners are curious:
Can raw beef, bones or hooves expose my dog to Mad Cow Disease?
Does cooking beef, rather than feeding it raw, protect my dog?
Is it okay to feed deer and elk meats?
Let's take a look at Mad Cow Disease and what the experts have to say.
What Is Mad Cow Disease?
Bovine Spongiform Encephalopathy (BSE), or Mad Cow Disease, is a transmissible, slowly progressive, degenerative disease having an extremely long incubation period - - some experts quote three to nine years. The disease affects the central nervous system of cattle causing symptoms such as excessive salivation, staggering gait and weight loss. The animal usually dies within six months of becoming symptomatic.
The long incubation period means that there is a very long period where an animal is infected but does not appear ill.
BSE is caused by an abnormal version of a protein called a prion, which is scientific shorthand for proteinaceous infectious particle. The BSE found in cattle can be passed to humans through contaminated meat and has been named Variant Creutzfeld-Jakob Disease (vCJD).
BSE is part of a larger group of disease referred to as Transmissible Spongiform Encephalopathies (TSE). TSEs are neurological diseases pathologists have characterized by the tiny holes they inflict in brain tissue. When viewed under a microscope, they make the brain look like a sponge.
Currently, the nature of the transmission agent in is not understood. Several theories exist and the one most accepted is that the responsible agent is a modified form of a cell surface component known as a "prion protein."
Heating, boiling, cooking, freezing, ionizing, radiating, autoclaving, sterilizing, bleaching, or even using formaldehyde cannot kill prions. Scary, huh?
The most effective way to stop the spread of prion diseases, per the USDA and FDA, is through early identification and removal of any diseased cattle from the human food chain.
Let's first look at beef intended for our consumption, and how prion disease has affected it's processing, and then we'll focus on beef and those beef byproducts that are ingredients in our pets' foods.
Human Consumption of Beef Products
Mad Cow Disease was first implicated as causing vCJD in humans in the mid-1980s in Great Britain. The mode of transmission appears to be that infected animals were processed as cattle feed and then fed to other cattle that were then consumed by people. The BSE prion mutated and appeared in humans as vCJD.
There are limited portions of the steer carcass thought to carry the offending prion. They are the brain, spinal cord, and other nervous system tissues. These are referred to as specified risk materials (SRMs) by the FDA, USDA and meat packers.
BSE infectivity in cattle tissue is:
Spinal Cord 25.6%
All other tissue <1.0%
Muscle meats, experts state, should be safe for human consumption, even if they are from an infected steer. That said, no meat products from countries shown as having BSE or being at risk for it are permitted for importation into the American market.
While the USDA tells us that muscle tissue is safe, killing methods in slaughterhouses and the possible contamination of brain and central nervous tissue into other tissues during mechanical meat recovery make the countries of the European Union (EU) uneasy. Therefore, the EU banned all mechanically recovered meats (MRM) for human or domestic animal feed.
In the United States (U.S.), this ban on MRMs is scheduled for implementation only in products intended for human consumption, starting in July 2004, reported MSNBC on July 10, 2004. Excerpts follow:
"As of July 10, 2004, six months after the first reported case of Mad Cow Disease was found within the U. S., the FDA banned the use of some high-risk meat in foods and cosmetics. The new rule only mirrors a regulation put in place by the Department of Agriculture in January 2004 banning the use of "specified risk materials" in human food, dietary supplements and cosmetics, as well as the use of cattle that cannot walk and mechanically separated beef.
The Consumer Federation of America was extremely disappointed that the FDA did not take action on rules and regulations proposed back in January 2004 but instead called for "further comment." This prompted Jean Halloran, Director of the Consumer Policy Institute to say: "They are actually spinning their wheels backwards."
Milk and milk products, even from BSE infected cows, or from the 31+ countries now identified as having BSE or being at risk, are allowed into the U.S., as dairy products have not been shown, in laboratories, to cause TSE infections in the same or in other test animals.
Safety Measures and Concerns
The bottom line from government agencies is that striated muscle meats such as steaks, roasts and ground beef, together with fat, bone and milk are not infective, because they are not believed to contain [enough of] the BSE-causing prions and therefore are assumed safe for people, even if the source cattle were found to be infected.
Since the discovery of infected cows first in Great Britain, then in Canada, and now one (or possibly more) within the U. S., the USDA has announced implementation of some new safeguards. These safeguards fall far short of those called for by consumer groups and scientists. (See below.)
This new rule was very interesting to me, as a pet owner: "Meat from downer animals will no longer be allowed into our human food supply. These animals are called 4D for dead, dying, diseased and disabled. "
However, 4D animals can still be used in commercial pet foods and feed for poultry and swine.
Restrictions have also been placed on slaughter and processing methods to "increase the likelihood" tissue from the nervous system of the cow does not end up in meat products. I don't know about you, but I'd personally prefer the phrase "positively prevent."
New and better methods of tracking cattle have also been proposed and debated. Final determinations on tracking and record keeping requirements, like many other suggestions, are still "pending" before various groups and committees within the USDA.