Health Foods Bark Up Wrong Tree : Pets: Adequate nutrition is all a healthy dog or cat needs, veterinarians say. They warn against extra vitamins and insufficient fat in the diet.

The idea of feeding Fido or Fluffy pulverized chicken feet and fish heads may rankle health food enthusiasts, but experts say those and other meat byproducts are just as nutritious as fancier tidbits, and usually cheaper.

The dog and cat food industry--with sales approaching $7 billion a year--has exploded with new offerings that tout more natural ingredients, reduced fat content and fewer calories.

There’s Alpo Lite, “now with garden vegetables,” Nature’s Course, “free of beef and chicken byproducts,” and Purina O.N.E., for “optimum nutritional effectiveness.” And more costly varieties are sold through catalogues, veterinarians’ offices and pet shops.

Are they more hype than health?

Regulators, veterinary nutritionists and others say that most foods are the same nutritionally: adequate. Anything more, they say, is usually unnecessary for healthy pets, as well as a waste of money. Predictably, pet food makers and health-food advocates often disagree.

“The very best cat nutrition would be to go out and find a mouse and grind it up. It has the right kind of protein and everything is balanced,” said Joan Wastlhuber, chairman of the Health Committee of the Cat Fanciers’ Assn., a large registry of feline breeds.

“But the people are the ones that buy the food and open the cans and serve it, and (ground mouse) would look gray and ugly,” she said.

Assessing the nutritional value of a pet food is difficult, because regulators have no accepted method of doing so, said Richard Sellers of the American Assn. of Feed Control Officials (AAFCO), a group of industry regulators that sanctions nutritional standards and promotes uniform labeling.

In addition, most regulators don’t have the budgets or the facilities to do feeding tests, so they depend on manufacturers, he said.

“That gives me heartburn,” said Sellers, who supervises product regulation for Texas and chairs AAFCO’s Pet Food Committee. “There’s always this element of doubt. If you know what you’re doing you can fake that data real easily.”

Sellers’ group endorses pet food formulas that meet its definition of “complete and balanced,” meaning AAFCO endorses the food as adequate.

So what about foods promising better, or “optimum,” nutrition?

They’re probably unnecessary, said Dr. Francis Kallfelz, a professor of veterinary nutrition at Cornell University. “The grocery store variety of pet foods will essentially do the same job in almost any circumstances.”

Pet owners who buy specialty foods often don’t realize they often should feed the pet less of it, Kallfelz said. “The danger with these premium-type products is high nutrient density, high caloric density.”

So when Fluffy gets fat, her owner turns to low-cal food. There’s no way to determine how a dog or cat uses calories, so AAFCO doesn’t back calorie claims on labels, Sellers says.

“It’s a vicious cycle. If you want to make sure your dog isn’t fat, feed it less--but that doesn’t capture the marketing imagination,” he said.

Dr. David Dzanis, a veterinary nutritionist for the Food and Drug Administration, and Sellers said that some specialty foods, such as the low-fat types, can harm a pet.

Consumers sometimes don’t realize that “natural” preservatives mean the feed has a shorter shelf life, and one important preservative is animal fat. Without it, the feed spoils sooner and can make a four-legged loved one sick.

The most commonly used sources of protein and energy-producing ingredients in dog and cat foods are grains and meat and poultry byproducts, Sellers said.

These, Dzanis says, can include thoroughly ground and cooked concoctions of beet pulp, wheat middlings, corn meal, fish heads, chicken feet and animal organs.

To counter those and other ingredients that may not seem so great to humans, many pet food labels tout “real” beef and chicken and fewer byproducts, grain and vegetable-based protein. Grain, meat byproducts and proteins such as soybean “are perfectly acceptable nutritionally” and cost less, Dzanis says.

Pet food marketers object to the all-are-equal claim. They defend the ingredients in specialty brands as being of higher quality and more easily digestible.

Specialty foods are worth nearly $1 billion of the market, said Glenn Williams, manager of marketing communications for The Iams Co., which produces food sold in vets’ offices and pet stores.

“As the specialty pet foods have grown and grown, a lot of grocery people are casting an eye in our direction and trying to recoup the lost sales,” he said.

Patrick Farrell, a spokesman for the nation’s largest pet food maker, Ralston Purina Co., said that the premium brands “deliver a more effective form of nutrition.”

“It’s a matter of offering the consumers a variety that they’ve told us and showed us with the success of these products that they want in the marketplace,” he said.

Jan Salimbene, an animal rights activist and owner of Wow-Bow Distributors Ltd., offers vegetarian and chemical-free pet foods by mail order.

“We’re bombarded with chemicals every day. If there’s a niche that you stay away from them, I’m for staying away from them,” she said.

Iams came out in January with canned cat food free of “flavor enhancers” such as onion, garlic and sugar. They make the food taste better but have little nutritional value, Williams said. The food also is prepared without “appearance enhancers” such as vegetable gums, which don’t benefit cats.

Though some breeders and animal advocates suggest supplementing commercial foods, Sellers warns against it, because it throws off the nutritional balance. Too much calcium, for instance, can cause bone-development problems in growing dogs. Too much fat-soluble Vitamin D can cause kidney problems, Dzanis said.

AAFCO will not sanction claims of “100% natural” on pet food labels. “We proposed a very strong definition for natural that really wouldn’t have allowed anybody to say natural,” Sellers said.