What's Really in Your Rat's Food

The protein used in pet food comes from a variety of sources. When cattle, swine, chickens, lambs, or any number of other animals are slaughtered, the choice cuts such as lean muscle tissue are trimmed away from the carcass for human consumption. Whatever remains of the carcass -- bones, blood, pus, intestines, ligaments, and almost all the other parts not generally consumed by humans -- is used in pet food. These "other parts" are known as "by-products" or other names on pet food labels. The ambiguous labels list the ingredients, but do not provide a definition for the products listed.

The 4 D's

Condemned parts and animals rejected for human consumption can be rerouted into commercial pet foods. These condemned parts are referred to as the 4 D's: dead, dying, diseased or decayed. We believe this is one of the most despicable practices in the pet food manufacturing industry.

Some manufacturers have a lower standard regarding the quality of ingredients they use to make pet food. A recent example of this practice is the discovery of Pentobarbital in major pet foods, including supermarket brands. Pentobarbital is a chemical used to euthanize animals. Many holistic veterinarians feel that daily ingestion of pentobarbital can be harmful.

Many manufacturers cut costs by using the cheapest ingredients available at the time a food is made. Since costs rise and fall, some manufacturers will vary ingredients from batch to batch .. resulting in changed nutrient values for each batch and possible digestive illness.

Some manufacturers have lower standards regarding the freshness of ingredients they use to make pet food. You can not determine the freshness of ingredients by reading a label; you must trust the pet food manufacturer.

Animal and Poultry Fat

You may have noticed a unique, pungent odor when you open a new bag of pet food -- the smell of restaurant grease from a hundred fast food restaurants. What is the source of that delightful smell? It is refined animal fat, kitchen grease, and other oils too rancid or deemed inedible for humans.

Restaurant grease has become a major component of feed grade animal fat over the last fifteen years. This grease, often held in fifty-gallon drums, is usually kept outside for weeks, exposed to extreme temperatures with no regard for its future use. The next few times you dine out, be sure to look out back behind the restaurant for a container with a rendering company's name on it. It is almost guaranteed that you will find one. "Fat blenders" or rendering companies then pick up this rancid grease and mix the different types of fat together, stabilize them with powerful antioxidants to retard further spoilage, and then sell the blended products to pet food companies.

These fats are sprayed directly onto dried kibble or extruded pellets to make an otherwise bland or distasteful product palatable. The fat also acts as a binding agent to which manufacturers add other flavor enhancers as well. Pet food scientists have discovered that animals love the taste of these sprayed fats. Manufacturers are masters at getting a dog or a cat to eat something she would normally turn up her nose at.

Wheat, Soy, Corn, Peanut Hulls, and Other Vegetable Protein

The amount of grain products used in pet food has risen over the last decade. Once considered filler by the pet food industry, grain products now make up a considerable portion of pet food. The availability of nutrients in grain products is dependent upon the digestibility of the grain. The amount and type of carbohydrate in pet food determines the amount of nutrient value the animal actually gets. Dogs and cats can almost completely absorb carbohydrates from some grains, such as white rice. Up to 20% of other grains can escape digestion. The availability of nutrients for wheat, beans, and oats is poor. The nutrients in potatoes and corn are far less available than those in rice. Carbohydrate that escapes digestion is of little nutritional value due to bacteria in the colon that ferment carbohydrates. Some ingredients, such as peanut hulls, are used strictly for "filler" and have no nutritional value at all!

Aflatoxins are produced by Aspergillus flavus and Aspergillus parasiticus at any time during growth and postharvest storage of a number of foodstuffs, mainly peanuts, cottonseed, and corn in the U.S.  Fischer 344 rats readily develop liver cancer when exposed to aflatoxin B1.

Additives and Preservatives

Adding chemicals to food originated thousands of years ago with spices, natural preservatives and ripening agents. In the last 40 years, however, the number of food additives has greatly increased. Of the more than 8,600 recognized food additives today, no toxicity information is available for 46% of them. Cancer-causing agents are sometimes permitted if they are used at low enough levels. The risk of continued use at these cancer-causing agents has not been studied and the build up of these agents may be harmful. Ethoxyquin (EQ), for example, was found in dogs' livers and tissues months after it had been removed from their diet, and as of July 31, 1997, the FDA's Center for Veterinary Medicine requested that manufacturers reduce the maximum level for EQ be cut in half, to 75 parts per million.

While the law requires studies of direct toxicity of these additives and preservatives, most of these additives have not been tested for their effect on each other once ingested. Three commonly used preservatives, BHA, BHT, and EQ, have a proven synergistic effect that may lead to the development of certain types of cancer.

Butylated hydroxyanisole (BHA) and butylated hydroxtoluene (BHT) are the most commonly used antioxidants in processed food for human consumption. For these antioxidants, there is little information documenting their toxicity or the safety of long-term use in pet food.

Testing of rats showed that BHA and BHT inhibited growth, caused weight loss, damaged the liver, kidneys and testicles, caused the rat to go bald, and elevated the blood cholesterol levels. It also caused their offspring to be born without eyes, and there were indications of brain defects. These two related preservatives are further suspected of causing cancer and allergic reactions.

BHT also causes a lowering of prothrombin index in rats at doses as low as 0.017% of diet after one week (Takahashi 1978). This effect also attenuates with time.  After four weeks, prothrombin index was lowered only at 0.25% and 0.50% BHT.  At levels of 1.0-1.5%, dietary BHT causes hemorrhagic death in male rats (Takahashi 1981, 1978b, 1976b).  This effect may be due to inhibition of phylloquinone epoxide reductase (Takahashi 1981c) which allows accumulation of a prothrombin precursor in the microsomes of treated rats.  The hemorrhagic effect is completely blocked by phylloquinone (Vitamin K) or phylloquinone oxide (Suzuki 1979, Takahashi 1979).

(BHT has been banned for use in food in England, Romania, Sweden and Australia.)

In animal feeds, the most commonly used antioxidant preservative is ethoxyquin. While some pet food critics and veterinarians claim ethoxyquin is a major cause of disease, skin problems, and infertility in dogs, others claim it is the safest, most stable preservative available for pet food. Ethoxyquin is not approved for use as a preservative in human food, however.

Nitrate is the exception to the rule when it comes to safety. Nitrate is used in meat for human consumption. When nitrate combines with bacteria, the chemical can change to another form with carcinogenic properties called nitrosamines. Very small amounts of this chemical can cause acute and chronic liver damage.

Propylene glycol, a cousin to antifreeze.   Rats were administered propylene glycol in their diet or drinking water for up to 2 years. Concentrations greater than 25% in their drinking water were lethal to rats within 2 months and diets containing 40% or greater propylene glycol were lethal to rats in a few days. In one study, rats given propylene glycol in their diet at 5% for 24 months, developed very slight liver damage, visible only microscopically. No other organ damage was observed in any of the studies. The EPA has classified propylene oxide as a Group B2, probable human carcinogen.

"Natural preservatives" and antioxidants are known as Vitamin C, Vitamin E, and mixed tocopherols. While the avoidance of using pet food laced with chemical preservatives is something to consider, some critics think that natural preservatives are somewhat less effective than chemical preservatives.

What does "extruded kibbles" mean?

Most dry food is made with a machine called an extruder. Ingredients of a recipe are blended and then fed into the extruder where steam, pressure and high temperatures force the food through various shaped dies to determine the shape and they come through puffed like popcorn to produce more volume. The food is dried and then sprayed with the fat process mentioned above. Although the heating process is designed to kill bacteria in the food, it can lose it's sterility during the drying, fat spraying, or packaging process.

Top Pet Food Manufacturers

Nestle makes Alpo, Fancy Feast, Friskies, Mighty Dog, and Ralston Purina.

Heinz makes 9 Lives, Amore, Gravy Train, Kibbles-n-Bits, and ... surprise! .... Nature's Recipe.

Colgate-Palmolive makes Science Diet.

Procter & Gamble, one of the major companies attacked for their repetitive animal testing, makes Eukanuba and Iams.

Mars makes Kal Kan, Mealtime, Pedigree, Sheba and Waltham's.

For more information on Rattie-Express or any of our animals, please email me (Tara) at rattie.express@comcast.net.