The most frequently asked question in my practice is: "Which commercial pet food do you
recommend?" My standard answer is: "None."
I am certain that pet-owners notice changes in their animals after using different batches of the
same brand of pet food. Their pets may have diarrhea, increased flatulence, a dull hair coat,
intermittent vomiting or prolonged scratching. These are common symptoms associated with
commercial pet foods.
In 1981, as Martin Zucker and I wrote How to Have a Healthier Dog, we discovered the full extent of
negative effects that commercial pet food has on animals. In February 1990, San Francisco
Chronicle staff writer John Eckhouse went even further with an expose entitled "How Dogs and Cats
Get Recycled into Pet Food."
Eckhouse wrote: "Each year, millions of dead American dogs and cats are processed along with
billions of pounds of other animal materials by companies known as renderers. The finished
product... tallow and meat meal... serve as raw materials for thousands of items that include
cosmetics and pet food." [See sidebar, ''The Dark Side of Recycling," Spring 1990 ElJ.]
Pet food company executives made the usual denials. But federal and state agencies, including the
Food and Drug Administration and medical groups, such as the American Veterinary Medical
Association and the California Veterinary Medical Association (CVMA), confirm that pets, on a
routine basis, are rendered after they die in animal shelters or are disposed of by health
authorities -- and the end product frequently finds its way into pet food.
Government health officials, scientists and pet food executives argue that such open criticism of
commercial pet food is unfounded. James Morris, a professor at the School of Veterinary Medicine
at Davis, California, has said, "Any products not fit for human consumption are very well
sterilized, so nothing can be transmitted to the animal."
Individuals who make such statements know nothing of the meat and rendering business.
For seven years, I was a veterinary meat inspector for the US Department of Agriculture and the
State of California. I waded through blood, water, pus and fecal material, inhaled the fetid stench
from the killing floor and listened to the death cries of slaughtered animals.
Prior to World War II, most slaughterhouses were all-inclusive; that is, livestock was slaughtered
and processed in one location. There was a section for smoking meats, a section for processing meats
into sausages and a section for rendering.
After World War II, the meat industry became more specialized. A slaughterhouse dressed the
carcasses, while a separate facility made the sausages. The rendering of slaughter waste also became
a separate specialty -- no longer within the jurisdiction of federal meat inspectors and out of the
To prevent condemned meat from being rerouted and used for human consumption, government
regulations require that meat is "denatured" before removal from the slaughterhouse and shipment
to rendering facilities. In my time as a veterinary meat inspector, we denatured with carbolic acid
(a potentially corrosive disinfectant) and/or creosote (used for wood-preservation or as a
disinfectant). Both substances are highly toxic. According to federal meat inspection regulations,
fuel oil, kerosene, crude carbolic acid and citronella (an insect repellent made from lemon grass)
all are approved denaturing materials.
Condemned livestock carcasses treated with these chemicals can become meat and bone meal for the
pet food industry. Because rendering facilities are not government controlled, any animal carcasses
can be rendered -- even dogs and cats. As Eileen Layne of the CVMA told the Chronicle, "When you
read pet food labels, and it says 'meat and bone meal,' that's what it is: cooked and converted
animals, including some dogs and cats."
Some of these dead pets -- those euthanized by veterinarians -- already contain pentobarbital
before treatment with the denaturing process. According to University of Minnesota researchers,
the sodium pentobarbital used to euthanize pets "survives rendering without undergoing
Fat stabilizers are introduced into the finished rendered product to prevent rancidity. Common
chemical stabilizers include BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene)
-- both known to cause liver and kidney dysfunction -- and ethoxyquin, a suspected carcinogen.
Many semi-moist dog foods contain propylene glycol -- first cousin to the anti-freeze agent,
ethylene glycol, that destroys red-blood cells.
Lead frequently shows up in pet foods, even those made from livestock meat and bone meal. A
Massachusetts Institute of Technology study titled "Lead in Animal Foods" found that a nine-pound
cat fed commercial pet food ingests more lead than the amount considered potentially toxic for
I have been practicing small animal medicine for more than 25 years. Every day, I see the
casualties of pet industry propaganda. But the professors in the teaching institutions of veterinary
medicine generally support an industry that has little regard for the quality of health in our
One last word of caution: meat and bone meal from sources not fit for human consumption has found
its way into poultry feed. This means that animal products rendered under questionable conditions
are fed to birds that may wind up on your table. Remember this when you are eating your next piece
of chicken or turkey.
Dr. Belfield is a graduate of Tuskegee Institute of Veterinary Medicine, now in private practice in
San Jose, California. Dr. Belfield established the first Orthomolecular Veterinary Hospital in the
US and is the co author of The Very Healthy Cat Book. This article first appeared in Let's Live
Magazine, May 1992.
Copyright 1996, Earth Island Journal