How to select Pet Food
Updated: Jun 4, 2022
Commercial pet food is a great convenience for busy caregivers. You want the best for your companion animals, but with a bewildering array of foods and claims to choose from, how do you decide what’s best for your animals?
Standards for Ingredients The pet food industry is huge and extremely profitable ($25 billion a year in revenue worldwide). While manufacturers may appear to have the best interests of your companion animals at heart, they are generally more concerned about their stock prices and bottom lines. This may be especially true of pet food manufacturers owned by large, diverse, multinational parent companies. What this means to you is that if an inexpensive ingredient is available to replace a costlier one, many companies will make the substitution to save money. A few companies pride themselves on their “fixed formulas,” meaning that they always use the same ingredients. This may be good … if the ingredients are of acceptable quality to begin with.
Pet food may be labeled as “complete and balanced” if it meets the standards set by a group called AAFCO, the Association of American Feed Control Officials. These standards were formulated in the early 1990s by panels of canine and feline nutrition experts. A food may be certified in two ways: (1) by meeting AAFCO’s published standards for content (“Nutrient Profiles”), or (2) by passing feeding tests or trials. While most researchers agree that feeding tests are superior in assessing the nutritional adequacy of a food, clinical experience as well as scientific studies have confirmed that even foods that pass feeding trials may still be inadequate for long-term maintenance. Also keep in mind that the standards set only “minimums” and “maximums,” not “optimums.” Commercial foods are designed to be adequate for the average animal, but not all foods will be suitable for an individual animal’s variable needs.
Problems Commercial pet foods and some pet food ingredients have been implicated in a number of diseases in companion animals. Allergic skin disease, obesity, food intolerance, inflammatory bowel disease, chronic ear infections, cystitis (bladder inflammation), bladder and kidney stones, certain heart diseases, pancreatitis, feline hyperthyroidism, hip dysplasia, canine mammary cancer, bloat, and diabetes all have nutritional components — that is, nutritional factors are suspected or known to play a role in inducing or perpetuating these diseases. Thus, it is crucial that we, as caregivers, pay close attention to what we are feeding our animals and how they are reacting to the food.
One potential problem with commercial pet food is pesticide residues, antibiotics, and molds contained in pet food ingredients. Meat from sick animals may be loaded with drugs, some of which are known to pass unchanged through all the processing done to create a finished pet food (such as penicillin and pentobarbital). Between 1995 and 1999, there were two major recalls of dry dog food by different manufacturers due to mold contamination of grain ingredients. Some fungal toxins are very dangerous. The second recalled food killed more than 20 dogs.
Another problem is the unpredictable quality of common pet food ingredients. By-products, by-product meal, meat and bone meal, and similar ingredients can vary widely in their nutrient composition. Bone meals in the U.S. have had a lead contamination problem for many years. The protein in a meal containing a large amount of bone may be poorly digestible and fail to provide adequate nutrition, even though chemical analysis will reveal an acceptable amount of amino acids.
One of the biggest problems with commercial foods is the processing they undergo. Meals are rendered (cooked) at moderate to high temperatures for hours. Extruded foods pass through a steam heat/high pressure device that allows them to “puff” into kibble shapes when they come out of the machine. Even though they move through the extruder quickly, the extreme conditions may alter or damage some nutrients.
Pet food manufacturers are aware of these factors, and most add sufficient extra vitamins, minerals and other nutrients to compensate for losses in the manufacturing process. However, because the AAFCO profiles set only minimums for many nutrients, tests have shown that some minerals may be added to the food in excessive amounts.
Pet Food Shopping Checklist The most reputable manufacturers of “superpremium” and “natural” foods agree with holistic veterinarians and other experts that the very best diet for your animal companion is one that you make yourself. A homemade diet, carefully balanced nutritionally and using organic foods, is closest to what Mother Nature intended. However, many of us do not have the time or energy to do home cooking, especially for multiple animals or large dogs. For those of us who rely, partially or entirely, on commercial foods for our animals, API has prepared a checklist to use in selecting a good-quality diet.
Extensive research has revealed that the pet food industry is extremely secretive. Manufacturers will not disclose very much information about the sources of ingredients, how they are processed, their quality control standards, or, in some cases, even where the food is made. Because the forty-odd manufacturers we contacted failed to provide us with accurate information, this API checklist gives you, the consumer, the best chance of selecting the best foods among the choices available.
When selecting a commercial food for your animal companion, make sure the label has an “AAFCO guarantee,” preferably one that references “feeding tests” or “feeding protocols” rather than Nutrient Profiles.
Never buy a food containing “by-product meal” or “meat and bone meal.” These rendered products are the most inexpensive sources of animal protein. The contents and quality of these meals can vary tremendously from batch to batch, and are not a reliable source of nutrition for your animal.
In general, avoid foods that rely on by-products as the sole source of animal protein. By-products consist of organs and parts either not desired, or condemned, for human consumption. An occasional can of by-product-based food may be okay, since, in the wild, carnivores do consume the whole prey including the organs, but these foods are not acceptable as a steady diet.
Look for a named meat or meal (“lamb” or “chicken meal,” for example, instead of the generic term “meat”) as the first ingredient.
Avoid generic or store brands. These may be repackaged rejects from the big manufacturers, and generally contain cheaper — and consequently poorer quality — ingredients.
Unless specifically recommended by your veterinarian, avoid “light,” “senior,” “special formula,” or “hairball formula” foods. These foods may contain acidifying agents, excessive fiber, or inadequate fats that can result in skin, coat and other problems.
In general, select brands promoted to be “natural.” While they are not perfect, they may be better than most. Several brands are now preserved with Vitamins C and E instead of chemical preservatives (such as BHA, BHT, ethoxyquin and propyl gallate). While synthetic preservatives may still be present, the amounts will be less.
Check the expiration date to ensure freshness.
When you open a bag of dry food, give it a sniff — if there is any rancid odor at all, return it immediately for an exchange or refund.
Store dry pet food in a sealed non-porous container (a large popcorn tin is ideal) in a cool, dry place. Canned food is best removed from the can and refrigerated in a glass or ceramic container.
Guidelines for Feeding Your Animal Companion
Change brands or flavors of dry food every three to four months to avoid deficiencies or excesses of ingredients which may be problematic for your animal.
When changing dry foods, mix 1/4 of the new food with 3/4 of the old food, and increase the new food a little each day. Some finicky animals may need a more gradual change over two or more weeks. Never let a cat skip more than one or two meals; return to the old food if necessary.
With any new food or supplement, watch for subtle changes in your dog’s skin and coat, appetite, energy level, mood, itchiness, discharges or odors, body weight, and the size and consistency of stool. If negative changes occur, try a different food. If the change persists, consult your veterinarian.
If your animal companion is on a prescription diet, check with your veterinarian periodically (at least every 6 months) to make sure the diet is still correct. Many conditions resolve over time, and a diet that was needed for a younger animal may be inappropriate when she is older.
It is usually preferable to feed one or two meals per day rather than leaving food out all the time. However, some medical conditions require more frequent feeding. Check with your veterinarian about recommendations for your animals.
Feed some canned food, which generally contains more animal protein and less grain than dry foods. Plain dry food does not clean the teeth and is not an essential for either cats or dogs. Cats in particular need at least 50% of their diet in the form of wet food to reduce the workload on the kidneys and keep the urine dilute. Cats with a history of bladder or kidney disease should not be fed any dry food.
Supplement all commercial pet foods with other foods, such as organic meats and steamed, pureed or finely grated vegetables (most cannot be very well digested by carnivores raw). Dogs may be supplemented with tofu and cooked grains; however, cats should receive minimal carbohydrates in the diet. (Plant products tend to raise urine pH and may predispose cats to urinary tract disease.) If you are supplementing more than 15-20% of the diet, however, you will need to consult one of the many available books or websites for information on balancing vitamins, minerals and other nutrients.
Other helpful supplements that are especially important when feeding commercial food include probiotics such as acidophilus, digestive enzymes, and the antioxidant vitamins E (alpha tocopherol) and C (either Ester C, calcium ascorbate, or sodium ascorbate).
Consider making at least some of your animal’s food at home. This lets you control the quality of the ingredients. There are many excellent books, articles, and websites available for more detailed guidelines on ingredients, proportions, and preparations. Even one or two home-made meals a week will be a significant improvement over feeding solely commercial pet foods.
Your veterinarian only sees your companion once a year. Since you are with her every day, it is essential that you monitor her general health and how she is responding to the food she’s eating. Changes in appetite, coat quality, weight, stool, urine, or water consumption may signal a problem with the food, or a more serious medical problem. Report these or any other unusual changes or behaviors to your veterinarian.
Vegetarian Pet Foods Dogs and cats are classified as carnivores, but many dogs can thrive on a vegetarian diet. There are several vegetarian and even vegan pet foods available which are supplemented with nutrients unavailable in plants. Your dog might do very well with one of these diets, or even with a balanced homemade vegetarian diet. However, you should watch your dog carefully for problems such as a dull coat, dandruff, low energy, diarrhea, or other symptoms. It can take months or even years for a deficiency to develop.
Cats have very specific metabolic requirements for several nutrients found only in animal products, such as taurine, pre-formed Vitamin A (they cannot convert the plant precursor, beta-carotene), and arachadonic acid. They may not be able to adequately digest some plant-based proteins. There is at least one product marketed as a feline supplement for vegetarian diets, but these nutrients are chemically synthesized or highly purified, and may lack the enzymes and co-factors needed for optimal absorption and function. The long-term implications of these supplements are unknown. Therefore, API does not recommend that cats be fed a strictly vegetarian diet.
Pet Food Label “Rules”
The 95% Rule: If the product says “Salmon Cat Food” or “Beef Dog Food,” 95% of the product must be the named ingredients. A product with a combination label, such as “Beef and Liver for Dogs,” must contain 95% beef and liver, and there must be more beef than liver, since beef is named first.
The 25% or “Dinner” Rule: Ingredients named on the label must comprise at least 25% of the product but less than 95%, when there is a qualifying “descriptor” term like “dinner,” “entree,” “formula,” “platter,” “nuggets,” etc. In “Beef Dinner for Dogs,” beef may or may not be the primary ingredient. If two ingredients are named (“Beef and Turkey Dinner for Dogs”), the two ingredients must total 25%, there must be more of the first ingredient (beef) than the second (turkey), and there must be at least 3% of the lesser ingredient.
The 3% or “With” Rule: A product may be labeled “Cat Food with Salmon” if it contains at least 3% of the named ingredient.
The “Flavor” Rule: A food may be labeled “Turkey Flavor Cat Food” even if the food does not contain such ingredients, as long as there is a “sufficiently detectable” amount of flavor. This may be derived from meals, by-products, or “digests” of various parts from the animal species indicated on the label.
This is an edited version of the Animal Protection Institute’s eye-opening investigative report, “What’s Really In Pet Food,” and FAQ sheet, “Selecting a Commercial Pet Food.” To read the report in full, print FAQ sheets, or learn more about Born Free formerly known as API], visit bornfreeusa.org. Reprinted with kind permission.