(1) Discussing what's in various bags and cans of commercial pet food is unproductive, because all these products are COOKED and consist mostly of STARCHES. Certainly, pet-food companies do their utmost to differentiate their products in consumers' minds and to achieve branded status. Brands are much more profitable than generic products in any consumer category.
I agree that a variety of foods is the best safeguard for a complete diet, for both human owners and their pets. For humans, a variety of whole, fresh foods is recommended by physicians and nutritionists. For pets, veterinarians and animal nutritionists recommend feeding a monotonous diet of a single cooked, starchy junk food. How can this make sense? Feeding a variety of cooked, starchy foods does not exactly address the nutritional problem, however. Despite branding and advertising, all kibbles have pretty much the same nutritional profile.
Kibbles must be primarily cooked starches that are required to manufacture dry foods that keep their shapes. Deceptive labeling regulations allow pet-food companies to put meats first in the ingredient list, implying meat is the primary ingredient, which is false. Ingredients' weights are measured prior to processing. Meat is 75% water. Corn, wheat, and soy fractions are dry to start. The final product has very little meat, compared to the amount of starch.
Deceptive labeling also allows pet-food companies to divide starches into several ingredients, such as wheat bran, wheat gluten, wheat protein, etc., so wheat does not appear first on the ingredient list. Corn can appear four or five times in the ingredient list. If consumers add up the amount of starch in the product, they would be outraged that companies are permitted to advertise kibble with whole chickens and rib roasts falling into the bag.
If you want to know how pet foods are made and why there is so little difference among kibbles that cost a pittance and those that cost three and four times as much, look at an excellent video (http://www.viddler.com/explore/jennifergoodwin/videos/4/) made by Elizabeth Hodgkins, DVM, Esq, and Marion Smart, DVM, Professor at University of Manitoba School of Veterinary Medicine. They show exactly why all kibble is pretty much the same cooked starches, whether based on corn, wheat, rice, potatoes, or tapioca. They also show how useless AAFCO guidelines really are.
(2) A very important point, often omitted from discussion of pet foods is TEXTURE. Commercial pet foods leave a gummy sludge on pets' teeth. Pets who are deprived of meaty bones to gnaw have no way to clean their teeth. Teeth become coated with plaque, leading to gingivitis and periodontal disease. Periodontal disease afflicts 85% of dogs and 70% of cats over two-years-of-age. Untreated, gum disease challenges the animal's immune system and pours infection into major organs. Heart, liver, kidney and other chronic diseases follow. These facts are publicized by veterinary organizations to lure pet owners into expensive dental treatments. If pets are simply allowed to gnaw on raw meaty bones, they do not develop dental problems in the first place. It's that simple. Food texture is critical to pets' health.
(3) Some (most) veterinarians are not informed about genetic and evolutionary research on canids in the past decade. They cling to convenient untruths that allow them to continue feeding carnivorous pets cooked starches that are literally killing them. Here's brief summary of recent research:
The genetic structure of wolves and dogs was finally mapped from 2000 to 2004. The origin of domestic dogs from wolves is firmly established. Dogs are related more closely to East Asian wolves than to European or North American wolves (1). All wolves and dogs belong to the same species. Other canids, such as coyotes, jackals, and foxes, are genetically more distant and distinct from wolves and dogs.
By tracing mitochondrial DNA, inherited only from mothers, researchers found several wolf origins for contemporary dogs. The study looked at the DNA of 654 dogs from 83 dog breeds and 38 Eurasian wolves. Three maternal DNA patterns accounted for more than 95% of dog genotypes, and these three sources came from East Asian wolf populations. Based on number of mutations found in the DNA sequences, researchers estimate that dogs became domesticated in several events (at least 5 unique mothers), beginning about 15,000 years ago.
Another group of researchers (2) studied 96 gene loci in 414 purebred dogs representing 85 breeds. They plotted the genetic relatedness of contemporary dogs and wolves. They found that genotypes of ancient Asian and Arctic breeds more closely resemble contemporary Eurasian wolves than they resemble other dog breeds. Specifically, Shiba Inu, Chow Chow, Akita, Alaskan Malamute, Basenji, Shar-pei, and Siberian Husky breeds cluster with contemporary wolf genotypes more closely than with other dogs breeds. Afgan Hound, Saluki, Tibetan Terrier, Llasa Apso, Samoyed, Pekingese, and Shih Tsu breeds are intermediate, sharing genotypes with both contemporary wolves and with other dog breeds.
Most dog breeds were created by human selective breeding for specific tasks or appearances. Breed isolation, however, is a relatively new phenomenon. Most dog breeds have existed as isolated breeding populations for less than 200 years, many for less than 100 years. Following wars, famines, and natural disasters, some dog breeds that became nearly extinct were re-established by interbreeding several related breeds.
Few pet owners look at their Poodles, toy terriers, and Chihuahuas and think "wolf". Yet, these small dogs are just as much wolves as dogs that bear more obvious resemblances to species-brothers. Small size in dogs is caused by a single gene (3) that has been imported into many breeds to downsize them. Dwarfism depends on a single gene and has been used to create the dwarf profile in dachshunds, basset hounds, bulldogs, and so forth. The rest of these dogs' genotype is still wolf.
Dogs would thank their owners for thinking "wolf" when they consider how to feed them. Perhaps, it is obvious that an Alaskan Malamute or a German Shepherd would appreciate the whole-prey diet their wolf-brothers thrive upon. It is not as obvious that toy dogs need the same diet, scaled down to their size.
Don't let "experts" in veterinarian clothing, or minced-veggie purveyors online, tell you dogs are omnivores, whose diet has been shaped by human leftovers. Wolves and dogs are "opportunistic carnivores", who kill and eat whole prey and scavenge off other predators' kills. They will eat human garbage, but a healthy diet for wolves and dogs is principally meats and meaty bones. Pet owners can easily provide a wolf-diet in appropriate amounts and sizes for their friendly domestic wolves.
(1) Savolainen, P., Zhang, Y, Luo, J, Lundeberg, J., & Leitner, T. (2002). Genetic evidence for an East Asian Origin of Domestic Dogs, Science, 298, 1610-1613.
(2) Parker, H., Kim, L.V., Sutter, N.B., Carlson, S., Lorentzen, T.D., Malek, T., Johnson, G.S., DeFRance, H.B., Ostrander, E.A., & Kruglyak, L. (2004). Genetic structure of the purebred domestic dog. Science, 304, 1160-1164.
(3) Sutter, N.B.and 20 coauthors, (2007). A single IGF1 allele is a major determinant of small size in dogs. Science, 316, 112-115.
The argument that dogs evolved distinctly from wolves more than 100,000 years ago is false. Domestication of dogs BEGAN only 15,000 years ago, and dogs and wolves continue to be cross-fertile populations.
The argument that dogs and wolves evolved to eat different diets because of human contact is false. Both wolves and dogs scavenge at human garbage dumps in many parts of the world. Garbage is not the preferred diet of either dogs or wolves, but they will eat whatever they can find when game is short. Domestic wolves are just as much predators as their wild brothers. Studies of feral dogs underline this point.
The argument that small breeds are less wolf-like than larger breeds is false. Toy and dwarf breeds have one or two gene loci that make them extremely small or dwarfed. 99.9999 % of their genes are the same as larger breeds and wolves.
There is much evidence from many perspectives to lead to the conclusion that dogs and cats thrive on whole prey or its equivalent -- raw-meaty-bones. Dogs/wolves can eat human waste materials, but they do not thrive in the long run on a grain-based diet.
(4) Some commentators argue that feeding pets meats and bones that from food animals is wasteful, competes with human consumption, and is inconsistent with good earth stewardship. First, consider that 50% of every cow raised for human consumption is waste. 40 to 50% of sheep, pigs, chickens, and turkeys are deemed waste. Second, pets are largely fed on human waste, whether through byproducts processed in rendering plants that make up the bulk of animal ingredients in commercial pet foods, or by feeding pets parts of animals humans do not prefer. Let me speak to the latter.
I live in Hawaii. We do not have a rendering plant in the state. Of beef raised on the Big Island (grass-fed, no hormones or antibiotics), 50% was going to the local landfill, before we founded a raw-pet-food co-operative. Now co-op members can feed their cats and dogs beef tracheas, kidneys, spleens, lungs, back-ribs, neck bones, liver, and other parts that are less popular on the human table. The beef producers are delighted to have a pet-food market, pets are thriving on real carnivore foods, and we are keeping huge amounts of animal waste out of the landfill. I think raw pet-food co-ops, which exist all over the US and the world, are very environmentally friendly.
Rendering plants are also essential to public health. Without them, communities would be inundated with wastes from food animals and euthanized pets. However unsavory rendered products may seem, they are a mainstay of commercial pet foods. One could certainly argue that pets help to rid the world of human wastes. I prefer to feed my own dogs and cat with raw meats and bones that would go to a rendering plant elsewhere or to a landfill here. No apologies needed.