Recently many pet owners have become interested in the idea of paleolithic feeding - that is, feeding the paleolithic diet of cat or dog's ancestor. Paleolithic feeding does not mean the same thing to everyone, so some definitions are in order:
· Paleolithic diets are high in meat and fat, and low in starches and sugars - they theoretically mimic the ancestral diet of dogs (the wolf) and cats (the African wild cat).
· Low carb diets are theoretically low in *digestible* carbohydrates such as starches and sugars, and high in meats. They should also be low in another type of carbohydrate - fiber - but this varies diet to diet.
· Grain-free diets contain no grains (such as wheat, corn, oats, rice, millet, amaranth, quinoa, barley, etc). Grain-free diets are not necessarily low in carbohydrates, which are instead found as potato, tapioca, or pulses in these diet formulations.
Raw diets contain raw meat, and are typically high in protein and fat. They may or may not contain starches, sugars, fiber from vegetables and fruits, nutraceutical additives, or vitamins and minerals.
In general, the increasingly popular trend is to feed a paleolithic diet. These high meat, high fat diets usually consist of muscle and organ meat, ground bone, and may or may not contain vegetables, or be complete and balanced. It is important to note that these homemade and commercial combinations are not really paleolithic at all, as wolves and feral cats would typically eat almost all parts of their prey including the toughest, least digestible parts containing primarily connective tissue*, nervous system; organs not available for consumer purchase like trachea, lymph nodes, spleen, etc; GI tract contents, etc. Commercially available meat has also been exsanguinated - blood was drained at slaughter, and blood is a very rich source of nutrients.
Also, prey animals have generally eaten wild foods, which give their flesh a very different nutrient profile than that of store-bought meats. Wild grains (and therefore wild prey animals) contain higher levels of healthy omega-3 fatty acids and other types of plant compounds as well. Conventional meat used in raw diets come from intensively raised cattle and chickens with unhealthy fat (that causes atherosclerosis and heart disease in people!).
(*These poorly digestible, high connective tissue parts are known as by-products when found on a pet food label. Note that many pet owners consider “by-products” unhealthy, when they are, in fact, part of the natural diet.)
More important is the question of whether domestic dogs and cats should eat a paleolithic diet at all. First, domestic pets are genetically different from their wild ancestors. Even the tiny amount of DNA that differs between dogs and wolves, or domestic and wild cats accounts for major variations in some visible traits, like the differences in size between a Great Dane and a Chihuahua, or the leg length of a munchkin cat, the ears of a Scottish fold, or the nose and haircoat of a Persian cat. The traits we cannot see, such as those regulating metabolic enzymes, differ just as greatly from those of wild animals.
Next, evolution has different plans for wild animals than we do for our pets. Wild animals eat diets that are high in protein and energy to support repeated production of offspring - as many and as much as possible. Repeated reproduction is associated with shorter life expectancy, and when the body is worn out from optimal reproduction, there is no further use for that individual in the population, so they die from exhaustion and inability to fend for themselves.
We have different plans for our pets - we want them around for 15 or more years, and we know that neutering them and keeping them thin adds many years to their lives in comparison to their wild ancestors We also know that preventing nutrient deficiencies through development of complete and balanced diets has been associated with an increase in life expectancy. Paleolithic diets are too high in fat for many of our pets whose most intense exercise is a few 30 minute walks or play sessions a day. In order to achieve our goals for our pets, we may not always be able to feed a paleolithic diet.
Formulated diets that are lower in fat may be appropriate, and they may contain sources of carbohydrates (such as corn, lentils, rice, sweet potato, etc). These are not just fillers - they can contain low-fat sources of protein, as well as vitamins, minerals and good fiber types.
Finally, while raw and paleolithic diets can occasionally be used to feed sick animals, this is just as often not true, as we need to intensively manage some nutrients such as phosphorus or copper or fat. These ill animals have progressive illness that, without nutritional management, would kill them. In fact, in the wild, animals with these conditions indeed die an early death. We are able to keep our sick pets happy and well for much longer with controlled nutrition, whereas in the wild, they wouldn't have a chance, even if they were well enough to find food. Geriatric, ill pets who live for months to years happily represent a very, very artificial situation, and a natural diet is likely the worst thing that could happen to some of them!
Raw and homemade fresh diets can be formulated to provide just about any nutrient profile required by your pet, and pets are individuals – some will do well on raw and paleolithic diets, and some will not. The ideal diet for your dog or cat is the one that produces the best long term (not just short term) results. I recommend that your pet's diet be balanced in calories, protein and other nutrients to maintain your pet's optimum condition, rather than conform to some standard that doesn't apply to his or her lifestyle.