The spice of life is variety, or so they say. If that’s true for people, what about our dogs and cats?
Pet food company advertising would have you believe that feeding one food (theirs!) for your pet’s entire adult life is the way to go. But that concept is all wrong. When you really think about it, it doesn’t even make sense!
For many of us, our pets are our children. So let’s imagine for a moment that you have a child, let’s say a 2-year old boy named Junior (of course!), and let’s imagine taking him to the pediatrician for a check-up. The doctor bustles in, looks Junior over, then plunks a big bag of Yummi-o’s down on the exam table.
“Good news,” he beams. “All the vitamins, minerals and a perfect balance of nutrients that Junior needs are right here in New Complete Yummi-o’s. Now all you have to do is make sure Junior gets three servings every day.” The doctor wags his finger at you as he continues in a serious voice, “Now, since this food is perfectly complete and balanced, you mustn’t feed Junior anything else—no apples or oatmeal or broccoli or peanut-butter-and-jelly sandwiches—because you might cause a nutrient imbalance!”
Well, this sounds a little weird, but you trust the pediatrician—after all, it’s his name you see on all the gold-embossed university degrees on the exam room wall—so you go ahead and put Junior on an all-Yummi-o’s diet.
Time passes, Junior grows, and by golly, it sure is cheap, easy and convenient to feed him. The next year you bring him in for his checkup, and the doctor is very pleased.
“He looks great,” says the doc. “I see you’ve been keeping him on Yummi-o’s. Terrific! Now, I have more good news for you! Yummi-o’s now comes in Life Stages! You’ll keep him on Yummi-o’s Growth until he starts kindergarten. Then he’ll go on Elementary Yummi-o’s until he hits middle school. Then you give him Adolescent Yummi-o’s until he’s 18, when he can be weaned onto the Adult formula. And it gets even better—you can eat it too! New Improved Yummi-o’s is complete and balanced for adults up to 65 years old.”
"Pet food company advertising would have you believe that feeding one food (theirs!) for your pet’s entire adult life is the way to go. But that concept is all wrong."
Ridiculous? Of course! What rational parent would feed a child only one food for years on end? Even if the food were, in fact, complete and balanced, most of us would consider it unnatural, even cruel to the child. Never give Junior a carrot or a glass of orange juice? No fresh food at all? Preposterous!.
Then why does everyone think it’s okay to feed a cat or dog that way?
We would think a pediatrician who recommended a single food diet for a child was bonkers, yet when the veterinarian recommends a single food for our pampered pet, we obey without question. But feeding a dog or cat is not all that different from feeding a child.
It’s way past time to bring a little common sense to bear, and common sense dictates that an animal ought to get a variety of foods.
The veterinary literature is full of cases where nutritional deficiencies (or excesses) were discovered, and in virtually every one, the problem arose (or was discovered) because the animal was kept on one food for a long period of time.
Cats, being strict obligate carnivores, have most often been the unintended victims—taurine, copper, vitamin E and potassium deficiencies have turned up in cats fed certain foods (which were, by the way, “complete and balanced” according to the standards at the time) as their sole diet.
Dogs, whose omnivorous metabolism is more adaptable, haven’t had quite as many problems, though zinc and fatty acid deficiencies have occurred on certain poor quality foods.
"It’s way past time to bring a little common sense to bear, and common sense dictates that an animal ought to get a variety of foods."
The Myth of Complete and Balanced
Wait a minute… aren’t we indeed talking about “complete and balanced” foods? How can a complete and balanced food have deficiencies or excesses of nutrients? Unfortunately, even for the best commercial pet foods, there are several places along the road to the retail store shelf where any food’s nutritional value can go astray.
- The standards by which the food is made aren’t perfect. Pet nutrition is an evolving science, and we don’t yet know all there is to know about it (if we ever will!). Veterinarians have seen many examples of how the particular nutritional needs of a species become known—mainly by stumbling on cases where they aren’t being met.
- The exact quantities of individual nutrients in a given ingredient may not be known, or may be inaccurately assessed. A shipment of barley might be presumed to have a certain nutritional composition based on analyses of previous batches, but depending on the weather where it was grown, the soil conditions, and the type of fertilizer used, the exact amounts of each nutrient may vary. The same applies to animal-based ingredients.
- Ingredient quality may be inconsistent or unknown. A vitamin-mineral premix purchased from an outside supplier and added to the food may guarantee minimum levels of each item, but if the quality control on that product was poor, the finished pet food will merely compound the error. Many vitamins and minerals are normally “overdosed” in pet food to make up for loss of those nutrients during processing, transport and storage. Some of these may present a health risk. For instance, iodine excess in cat foods is suspected of contributing to the skyrocketing incidence of hyperthyroidism in older cats; and a zinc overdose in a commercial dog food sickened author Ann Martin’s dogs and started her on a quest through the maze of pet food manufacturing and regulation, detailed in her stunning book Food Pets Die For in 1997.
- Processing alters many nutrients. The heat used in various stages of pet food manufacturing can alter many ingredients, some for the better and some for worse. Carbohydrates are made much more digestible by cooking, but proteins can be denatured, vitamins can be destroyed, and fats can be damaged by heat. In general, pet food manufacturers are aware of changes that occur in their products during processing, and compensate for heat-sensitive ingredients by adding supplements, such as extra vitamins, but alterations in proteins and fats are not generally accounted for.
- The pet food manufacturer itself can make mistakes. It’s obvious from feed reports from around the country that virtually every manufacturer—no matter how good, bad or indifferent its reputation—at one time or another fails one or more tests for protein, calcium, magnesium or other nutrients.
- Increased risk of toxic effects. As many people unfortunately discovered in last year’s recalls, feeding the same food, from the same manufacturer, who continually buys from the same suppliers, can lead to health problems for your animal companion. While some of the recalled foods had such huge amounts of melamine that even one serving was deadly, feeding a variety of foods could have “diluted” the effect of the toxin and caused less harm for thousands of pets.