I’m in California this week (May 2012) visiting family…and there are so many interesting things happening here! But of course, the one that may most profoundly affect our pets is the discovery of a cow infected with Bovine Spongiform Encephalopathy (BSE or “Mad Cow Disease”).

The cow was, as usual, a dairy cow. Dairy cows are the only cattle that stay alive long enough for BSE to be an issue, as the disease takes several years to incubate and manifest. Beef cattle are typically slaughtered too young to show symptoms. Males of dairy breeds are also fattened up and slaughtered young; their meat is mostly used for inexpensive hamburger.

We have had BSE in the U.S. for decades. However, as soon as evidence of this fact became public, the USDA reduced the number of cows it tests for the disease. Currently, fewer than 50,000 cows per year are tested, out of the 35 MILLION cows slaughtered every year. It’s very hard to find something you are specifically not looking for, but somehow this cow managed to be caught anyway.

The prions (abnormal proteins) that cause BSE are not destroyed by rendering, cooking, chemical decontamination, or even incineration. It was recently discovered that they can be transmitted by aerosol. People and cats are quite susceptible to the disease. Some experts believe that many cases of BSE in humans are mis-diagnosed as Alzheimer’s or senility. There is a strong disincentive to know the truth about BSE in the United States, because it is such a scary disease. But we have it. Lots of it.

If you want to protect yourself and your pets from BSE, you must avoid all beef and mutton products (mutton may contain similar prions that, in sheep, cause a disease called “scrapie.”). In pet food terms, you would want to avoid all forms of beef, including “meat by-products,” “meat and bone meal,” “beef and bone meal,” “animal digest,” “animal fat,” and any mammal product not specifically designated as something else (“lamb,” for instance). Even that may not be enough, since “lamb” may contain beef parts; the name “lamb” can be applied as long as lamb is the predominant ingredient (i.e., at least 51% of the product). The term “meat” is restricted to cattle, sheep, goats, and swine, so any product simply designated as “meat” will usually contain beef.

For more details on this disease and its real history in the U.S., please see our article, Mad Cow Disease and Your Pets.