Perceived Benefits of Natural or Vegetarian Diets
Feeding dogs a diet similar to that of wild dogs or wolves (ie, low in grains or carbohydrates) has a popular following. Some clients opt to feed bones and raw foods, thought to be similar to a wolf eating a carcass or a cat catching prey. Clients should be reminded that dogs have been domesticated over the past 10,000 to 15,000 years, during which time their diet involved greater consumption of grains. Their genetic makeup evolved to accommodate this increase in dietary carbohydrates, and today dogs are genetically dissimilar to wolves in several key genes that involve starch digestion and glucose uptake.2 Many other metabolic traits were unaffected by domestication, and dogs as well as cats select a rather low-carbohydrate diet by choice, although both species can digest carbohydrates. Cats are obligate carnivores, requiring higher protein (generally meat, fish, or poultry) levels than do dogs.
Safety of a Raw Diet
Clients may be misinformed about the safety of raw diets. Studies on bacterial contamination of raw foods found that 20% to 35% of raw poultry and 80% of raw food diets for dogs tested positive for Salmonella spp, and 30% of stool samples from dogs fed these diets were positive for Salmonella spp.4 Raw food diets also have tested positive for Escherichia coli and Yersinia enterocolitica.4 Some otherwise healthy dogs may be able to cope with ingestion of these bacteria, but very young, old, or immunocompromised dogs may not. Furthermore, their feces can contaminate the environment, posing a risk to humans and other animals.
The close proximity of pets to human beings is an important zoonotic concern, and small children, the elderly, and the immunocompromised could become desperately ill secondary to exposure to pathogens that can be found in raw meat.
Parasites that may be present in raw meat include Echinococcus spp, Neosporacaninum, Sarcocystis spp, Toxocara canis, Toxoplasma gondii, and Taenia spp.4,6,7When handling raw food, the preparer must practice scrupulous hygiene, washing all surfaces and hands before touching anything or anyone else.
Tipping the Balance: Homemade Feeding Programs
Essential Nutrient Needs
Clients should understand that homemade and raw- food feeding programs are meant to balance pets’ diets over weeks, rather than after an individual meal. This can be achieved with correct ingredients, but almost no homemade diet recipes (when tested) were found to be balanced, whether fed via a single diet or several rotating diets, for all essential nutrients.
One nutritional study of the bones and raw-food (BARF) diet showed it to be deficient in calcium, phosphorus, potassium, and zinc and excessively high in vitamin D.4,5Varying foods would unlikely balance the deficiencies in homemade diets; recipes, regardless of ingredients, were deficient in the same nutrients.
Some adult pets can cope with some imbalances for months to years before clinical signs become apparent, but these imbalances may have serious effects on growing animals, even if the diet is fed for only a short time.