Nutritious food for Fido. (Homestead pets).

If you read the label on the back of the bag of dry, dog food, you might think you re reading the label on a nutrient-enriched loaf of bread, a box of kids' cereal or a vitamin supplement. The packages boast "Gentle fiber sources that help improve colon health and antioxidants for a healthy immune system."

There are specially-mixed recipes for puppies, active dogs, large dogs, senior dogs, and inactive dogs. There are even recipes for dogs who need weight-loss or maintenance diets.

Some dog food recipes were developed specifically with dog owners in mind. "Dog food companies looked at their demographics and realized that a lot of dog owners lived in high rise apartments or worked all day so they needed the dog to be able to be walked once in the morning and again in the evening without having to go out during the day," said George Fahey, a comparative nutritionist at the University of Illinois in the College of Agricultural, Consumer and Environmental Sciences. "Pet food companies have developed nutritionally balanced diets for those dogs confined to the home for up to half a day."

Fahey said that diets high in protein and fat can be both good for the dog and convenient for the owner. The labels on these recipe blends make statements like "Concentrated nutrition enables you to feed less. More nutrients stay in your dog so there's less backyard clean-up for you. Highly digestible so more nutrients go to work inside your dog and less pass through as waste."

Dog food producers relied on university research to help them find the right balance of protein, fat and fiber to include in the recipe for stay-at-home dogs.

Like human food, dog food is regulated. Diets are tested according to Association of American Feed Control Officials protocols. "Whenever there's a new ingredient added to human foods, about eight months later, we are asked to study it for use in dog foods," said Fahey.

Companies that make dog food, and the companies that supply ingredients to them, need to know how dogs will be affected by a certain ingredient or recipe. They can't do the research themselves, since it may be considered to be biased, so they come to an academic institution like the University of Illinois to get an unbiased evaluation and there aren't a lot of universities doing this kind of research.

"Despite the fact that there are 61 million dogs and 77 million cats in the world, there is less research about the nutrients they need as compared with livestock", said Fahey. In 1976, he was working with fistulated cows, that is, cows that have a hole in their side so that their digestion can be observed and material collected easily. When he saw the need for research to develop more nutritionally balanced food for dogs, Fahey switched to conducting research on canines.

"Dogs and cats suffer gastrointestinal problems, too, like constipation, diverticulitis and inflammatory bowel syndrome," said Fahey. "Racing greyhounds, sled dogs and other working dogs like police dogs and seeing eye dogs can experience great stress that can contribute to these gastrointestinal problems. Couch-potato dogs don't have stress but they have health problems brought on by obesity, like some humans."

To find answers to digestibility questions, researchers need access to the dog's gastrointestinal contents. "We need to know more than just what is being fed and about the nutrients excreted in feces," Fahey said.

In order to access the gastrointestinal material, a tube is inserted into the dog's terminal ileum "the last part of the small intestine." "We want to collect a sample before it reaches the large intestine where the microbial population breaks the food down," said Fahey. "That's where we collect the material so we know what's actually happening in the stomach and small intestine."

Fahey compared the procedure to an ileostomy in humans except that unlike an ileostomy in which the large bowel is removed so the person no longer has a colon, in the dog, nothing is actually removed. "And it doesn't harm the dog a bit", said Fahey. Like the fistulated cows at the University of Illinois, the dogs are not bothered by the tube in their side either.

There are only six to 10 dogs housed in the disease-free animal facility at the University of Illinois. How can Fahey's research team get accurate data from such a small number of dogs? "We use an experimental design called the Latin Square in which each dog serves as its own control," he said. "Say, for example, we are comparing four different diets. Each dog is rotated through the different diets. It works well."

Why all of this research on dog diets? Fahey said that dogs are omnivores like humans so they could survive nicely eating the same food we do. "But dog owners typically wouldn't fix a full plate of what's for dinner for their dog. They'd feed them dog table scraps and table scraps are not complete and balanced nutritionally. Each morsel of dog food is complete and balanced for nutrients, though."

There's no doubt that research will continue to be in demand to develop better dog food recipes not just for the dog's health, but also for economic reasons. After all, pets are big business.

The pet industry as a whole amounts to $39 billion worldwide, with $27 billion of that in pet food alone, the rest is made up in toys, drugs, cages, etc. In fact, 37% of households in the U.S. own a dog. A close second--35% of U.S. households own a cat.

DEBRA LEVEY LARSON
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