Pet Nutrition
Selecting A Commercial Pet Food
                   Animal Protection Institute

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.


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

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.

Our 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.

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.

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 dangerous
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

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
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
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.

[See table in article
Pet Food Labels Part Two]

The "Flavor" Rule: A food may be labeled or "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.

For more details see API's full investigative report on
"What's Really In Pet Food."
(Revised 10/25/00)
Pet Nutrition
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