PLUMP whole chickens, choice cuts of beef, fresh grains and all the wholesome nutrition your dog or cat will ever need. These are the images pet food manufacturers promulgate through the media and advertising. This is what the $11 billion per year United States pet food industry wants consumers to believe they are buying when they purchase their products.

This report explores the differences between what consumers think they are buying and what they are actually getting. It focuses in very general terms on the most visible name brands - the pet food labels that are mass distributed to supermarkets and discount stores - but there are many highly respected brands that may be guilty of the same offences.

What most consumers don't know is that the pet food industry is an extension of the human food and agriculture industries. Pet food provides a market for slaughterhouse offal, grains considered "unfit for human consumption," and similar waste products to be turned into profit. This waste includes intestines, udders, oesophagi, and possibly diseased and cancerous animal parts.

Three of the five major pet food companies in the United States are subsidiaries of major multinational food production companies: Nestlé (Alpo, Fancy Feast, Friskies, Mighty Dog), Heinz (9 Lives, Amore, Gravy Train, Kibbles n Bits, Recipe, Vets), Colgate-Palmolive (Hill's Science Diet Pet Food). Other leading companies are Procter & Gamble (Eukanuba and Iams), Mars (Kal Kan, Mealtime, Pedigree, Sheba) and Nutro. From a business standpoint, multinational food companies owning pet food manufacturing companies is an ideal relationship. The multinationals have a captive market in which to capitalise on their waste products and the pet food manufacturers have a reliable source from which to purchase their bulk materials.

There are hundreds of different pet foods available in the US - many of them commonplace on New Zealand retail shelves. And while many of the foods on the market are virtually the same, not all of the pet food manufacturing companies use poor quality and potentially dangerous ingredients.

Ingredients
Although the purchase price of pet food does not always determine whether a pet food is good or bad, the price is often a good indicator of quality. It would be impossible for a company that sells a generic brand of dog food at $9.95 for a 20kg bag to use quality protein and grain in its food. The cost of purchasing quality ingredients would be much higher than the selling price.

A bad skin rash such as photographed here may be caused through allergy to its current pet food, or one or more of the ingredients - or to something else it regularly eats or touches.

The Pet Food Institute - the trade association of pet food manufacturers - acknowledges the use of by-products in pet foods as additional income for processors and farmers: "The growth of the pet food industry not only provided pet owners with better foods for their pets, but also created profitable additional markets for American farm products and for the by-products of the meat packing, poultry and other food industries which prepare food for human consumption."

Many of these remnants provide a questionable source of nourishment for our animals. The nutritional quality of meat and poultry by-products and meals can vary from batch to batch. James Morris and Quinton Rogers, two professors with the Department of Molecular Biosciences, University of California at Davis Veterinary School of Medicine, assert that: "There is virtually no information on the bioavailability of nutrients for companion animals in many of the common dietary ingredients used in pet foods. These ingredients are generally by-products of the meat, poultry and fishing industries, with the potential for a wide variation in nutrient composition. Claims of nutritional adequacy of pet foods based on the current Association of American Feed Control Officials' (AAFCO) nutrient allowances (profiles) do not give assurances of nutritional adequacy and will not until ingredients are analysed and bioavailability values are incorporated."

Meat and poultry meals, by-product meals, and meat-and-bone meal are common ingredients in pet foods. The term "meal" means that these materials are not used fresh, but have been rendered.

What is rendering? Rendering, as defined by Webster's dictionary, is "to process as for industrial use: to render livestock carcasses and to extract oil from fat, blubber, etc, by melting". Home-made chicken soup, with its thick layer of fat that forms over the top when the soup is cooled, is a sort of mini-rendering process. Rendering separates fat-soluble from water-soluble and solid materials, and kills bacterial contaminants but may alter or destroy some of the natural enzymes and proteins found in the raw ingredients.

What can the feeding of such products do to your companion animal? Some veterinarians claim that feeding slaughterhouse wastes to animals increases their risk of getting cancer and other degenerative diseases. The cooking methods used by pet food manufacturers - such as rendering and extruding (a heat-and-pressure system used to "puff" dry foods into nuggets or kibbles) - do not necessarily destroy the hormones used to fatten livestock or increase milk production, or drugs such as antibiotics or the barbiturates used to euthanise animals.

Animal and poultry fat
You may have noticed a unique, pungent odour when you open a new bag of pet food - what is the source of that delightful smell? It is most often rendered animal fat, restaurant grease, or other oils too rancid or deemed inedible for humans.

Restaurant grease has become a major component of feed-grade animal fat over the last 15 years. This grease, often held in 50-gallon drums, is usually kept outside for weeks, exposed to extreme temperatures with no regard for its future use. "Fat blenders" or rendering companies then pick up this used grease and mix the different types of fat together, stabilise them with powerful antioxidants to retard further spoilage, and then sell the blended products to pet food companies.

These fats are sprayed directly on to dried kibbles 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 flavour enhancers. 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, peanut hulls, and 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, cereal and grain products now replace a considerable proportion of the meat that was used in the first commercial pet foods. The availability of nutrients in these 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 percent of the nutritional value of other grains can escape digestion. The availability of nutrients from wheat, beans, and oats is poor. The nutrients in potatoes and corn are far less available than those in rice. Some ingredients, such as peanut hulls, are used for filler or fibre, and have no significant nutritional value.

Two of the top three ingredients in pet foods, particularly dry foods, are almost always some form of grain products. Pedigree Performance Food for Dogs lists ground corn, chicken by-product meal, and corn gluten meal as its top three ingredients. Of the top four ingredients of Purina O.N.E. dog formula - chicken, ground yellow corn, ground wheat, and corn gluten meal - two are corn-based products ... the same product. This industry practice is known as splitting. When components of the same whole ingredients are listed separately - such as ground yellow corn and corn gluten meal - it appears there is less corn than chicken, even though the combined weight of the corn ingredients may outweigh the chicken.

In 1995, Nature's Recipe pulled thousands of tons of dog food off the shelf after consumers complained that their dogs were vomiting and losing their appetite. Nature's Recipe's loss amounted to $20 million. The problem was a fungus that produced vomitoxin and mycotoxin, toxic substances produced by mold contaminating the wheat. In 1999, another fungal toxin triggered the recall of dry dog food made by Doane Pet Care at one of its plants. This included 54 brands. This time, the toxin killed 25 dogs.

Although it caused many dogs to vomit, stop eating and have diarrhoea, vomitoxin is a milder toxin than most. The more dangerous mycotoxins can cause weight loss, liver damage, lameness, and even death as in the Doane case. The Nature's Recipe incident prompted the Food and Drug Administration (FDA) to intervene. But Dina Butcher, Agriculture Policy Adviser for North Dakota Governor Ed Schafer, concluded that the discovery of vomitoxin in Nature's Recipe wasn't much of a threat to the human population because "the grain that would go into pet food is not a high quality grain".

Soy is another common ingredient that is sometimes used as a protein and energy source in pet food. Manufacturers also use it to add bulk so that when an animal eats a product containing soy he will feel more sated. While soy has been linked to gas in some dogs, other dogs do quite well with it. Vegetarian dog foods use soy as a protein source.

Additives and preservatives
Many chemicals are added to commercial pet foods to improve the taste, stability, characteristics, or appearance of the food. Additives provide no nutritional value. Additives include emulsifiers to prevent water and fat from separating, antioxidants to prevent fat from turning rancid, and artificial colours and flavours to make the product more attractive to consumers and more palatable to their companion animals. 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.

All commercial pet foods contain preservatives. Some of these are added to ingredients or raw materials by the suppliers and others may be added by the manufacturer. Because manufacturers need to ensure that dry foods have a long shelf life to remain edible after shipping and prolonged storage, fats included in pet foods are preserved with either synthetic or "natural" preservatives. Synthetic preservatives include butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), propylgallate, propylene glycol (also used as a less-toxic version of automotive antifreeze), and ethoxyquin. For these antioxidants, there is little information documenting their toxicity, safety, or chronic use in pet foods that may be eaten every day for the life of the animal.

Potentially cancer-causing agents such as BHA, BHT, and ethoxyquin are permitted at relatively low levels. The use of these chemicals in pet foods has not been thoroughly studied and long-term build-up of these agents may ultimately be harmful. Due to questionable data in the original study on its safety, ethoxyquin's manufacturer, Monsanto, was required to perform a new, more rigorous study. This was completed in 1996. Even though Monsanto found no significant toxicity associated with its own product, in July 1997, the Food & Drug Administration's (FDA) Centre for Veterinary Medicine requested that manufacturers voluntarily reduce the maximum level for ethoxyquin by half, to 75 parts per million. While some pet food critics and veterinarians believe that ethoxyquin is a major cause of disease, skin problems, and infertility in dogs, others claim it is the safest, strongest, most stable preservative available for pet food. Ethoxyquin is only approved for use in human food for preserving spices, such as cayenne and chilli powder, at a level of 100 ppm - but it would be very difficult to consume as much chilli powder every day as a dog would eat dry food.

Some manufacturers have responded to consumer concern, and are now using "natural" preservatives such as Vitamin C (ascorbate), Vitamin E (mixed tocopherols), and oils of rosemary, clove, or other spices, to preserve the fats in their products. Other ingredients may be individually preserved. Fish meal and some prepared vitamin mixtures used to supplement pet foods contain chemical preservatives. This means that your companion animal may be eating food containing several types of preservatives. Not all of these are required to be disclosed on the label.

This report from the American Animal Protection Institute is published on that organisation's website and reprinted with their kind permission. Although some of the brands and products are not available in New Zealand, some are. Most of the research into pet foods has been done over a number of years, but the report was last updated last year. The food content in itself seems not too controversial - it is the quality of it that is in question - as is the quality of the oils, the grains and vegetables, and the percentage of some grains to protein. But most worrying of all is the preservatives used and the fact that some ingredients are already loaded with preservatives and chemicals before they are added to the recipe.

I invite Kiwi dog food companies to provide this magazine with a COMPLETE list of ingredients (meal, byproducts etc are NOT ingredients as they could contain anything!) including all preservatives and with all the names in common English (don't say amino acids if you mean monosodium glutamate, etc). If you can do that and if you are happy to have such a list published at any time, you can be sure of the approval of this magazine. We do not expect dog food to contain A-grade top quality meat and vegetables ... but we do expect that our dogs will remain healthy and gain the necessary nourishment without contracting any diseases or toxins. - Editor