Cats are obligate carnivores, and experts say meat should be their primary source of protein for proper health. But not all meat is created equal. It is better, say experts, to look for specific origins when it comes to ingredients. "Chicken meal," for example, consists of chicken flesh and skin, without bone, feathers, organs, etc. A label that says "meat meal," however, doesn't indicate a source and can come from just about any animal. Experts say beef meal is a lesser-quality protein source for cats than chicken meal.
In dry foods, seeing meat at the top of an ingredient list can be a little misleading, as meat has a high water content that's removed when it is processed into dry cat food. Meal, on the other hand, is meat with the water removed, and finding it high up in the ingredient list is a good indication of a high-protein dry food. As with wet varieties, better dry cat foods will identify the source of the meal.
Just as for human food, there are regulations regarding the labeling of cat food that can help consumers assess the amount of meat in the food. If a product is labeled "beef cat food," for example, 95 percent of its ingredients must be beef. If it says "chicken dinner" or "lamb formula," the named meat only needs to be 25 percent of the ingredients. If the packaging simply states "chicken flavor," the food merely needs to taste like chicken to the cat (though how that's ascertained is a bit of a head-scratcher); it does not need to actually have any chicken in it.
For protein, many cat foods use meat byproducts. There are two schools of thought regarding the use of byproducts in pet food. One point of view says that in the wild, a cat will eat every part of its prey -- bones, fur, internal organs and all -- therefore byproducts are a part of a cat's natural diet, so a small amount of byproduct might not be too bad. Among those with that point of view are veterinarian Lisa A. Pierson, whose CatInfo.org website says, "The whole issue of byproducts or no byproducts is a personal one." Pierson goes on to say that byproducts at least are of animal origin and don't add carbohydrates to the food. She adds that it is more sensible to include small amounts of animal-derived byproducts in a carnivore's diet than it does to add grains like corn, wheat or soy, which add carbs to the diet and could trigger an allergic reaction in some cats.
Others, such as Franny Syufy, the About.com guide to cats, aren't so sure. While Syufy allows that byproducts of named meats, such as chicken by-product meal, may be acceptable, she would prefer it be listed far down on the label. Premium cat foods recommended by most experts contain few, if any, byproducts.
You also might see an ingredient called "animal digest," which is the dry or liquid byproduct of the meat-rendering process. Experts say that while there is meat content in animal digest, it's of little nutritional value as it is not very digestible. Animal digest is almost never found in top-quality cat foot brands.
Artificial preservatives also give cat owners pause. There have been no studies done to determine the effects of long-term buildup of preservatives. Even so, the use of preservatives in human food has become a concern, and that has extended to pet food. Based on customer concerns, the best cat foods have switched to vitamins C or E as preservatives rather than chemical preservatives. If you decide to avoid artificial preservatives, check the label. Some common names of these chemicals include BHA/BHT, ethoxyquin and propyl gallate. Adding to the complexity of finding the best cat food, Susan Thixton explains in her blog, Truth About Pet Food, that pet food can include preservatives not listed on the label -- as long as they're added to an ingredient before it reaches the cat-food manufacturer.
Carrageenan is a thickening agent that's obtained from red seaweed. It's a common ingredient in lots of human food, ranging from infant formula to ice cream, and is found in the majority of canned cat foods, including some premium brands. Susan Thixton is among those that say it's not an ingredient we'd want to see in pet food because of research done on human tissue. The Center for Science in the Public Interest labeled carrageenan a safe ingredient at the time of our last update, but has since changed that to say that it should be used with caution. The Center continues to note that the amounts in food are typically too low to be of a concern, though there are indications that eliminating it from their diet has helped minimize discomfort in some with intestinal disease. If you cat is prone to digestive issues, choosing a food that does not include carrageenan might be well worth considering.
Even what is used to line cans comes in for some concern. Most food cans -- including those for human food -- have a lining that contains BPA (bisphenol A) so that the food doesn't come in contact with the metal. The amount of BPA in these linings is judged to be low enough by the FDA to be considered safe, but some advocates remain unconvinced as high levels of the chemical have been linked to cancer, reproductive problems and other diseases in humans. In cat foods, it's possible to find smaller cans (6-ounces or less) without BPA linings, but not larger cans.
Reviews say cats need meat much more than carbohydrates, and some say cats don't need carbohydrates at all. In general, foods that contain primarily high-quality protein -- meat, rather than meat byproducts or grain fillers -- rank much higher in reviews. Some premium foods do include some vegetables or berries. Most experts say cats don't need any grains at all, but that if a grain is included, rice is much less apt to cause an allergic reaction than cheaper grains, such as corn or wheat.
Many supermarket brands use comparatively more carbohydrate filler. This means your cat needs to eat more food in order to get the protein he or she needs. That, in turn, can impact your food costs in the long run, as well as your cat's overall health.