I have previously discussed studies of recipes for homemade diets, from books and the internet, which show that these diets are rarely nutritionally adequate or reliable in terms of consistently providing predictable levels of critical nutrients. Recipes for kidney disease, cancer diets, and raw diets have all been evaluated and found wanting. Now the largest study yet looking at the nutritional adequacy of homemade diet recipes has been published and—surprise, surprise—it has found that almost none of the recipes evaluated provide recommended levels of important nutrients.
Stockman, J. Fascetti, AJ. Kass, PH. Larsen,JA. Evaluation of recipes of home-prepared maintenance diets for dogs. Journal of the American Veterinary Medical Association. 2013;242(11): 1500-1505.
Two-hundred recipes were evaluated, including 129 written by veterinarians. The vast majority were vague about ingredients, feeding instructions, or the details of recommended supplements. Only 5 recipes could be interpreted as providing adequate levels of all essential nutrients as established by the National research Council guidelines, and only 9 recipes met the nutrient standards of the Association of American Feed Control Officials (AAFCO).
Despite common claims that nutritional adequacy can be met by rotating through a variety of foods even if no specific recipe is complete in itself, the authors found that when such groups of recipes were evaluated, they still did not provide a nutritionally complete diet even when fed in rotation as directed. Even though most recipes written by veterinarians were incomplete, those recipes provided by non-veterinarians were significantly more likely to be incomplete and were more likely to have more severe deficiencies. All 4 recipes written by board-certified veterinary nutritionists were complete. This pretty clearly demonstrates that claims veterinarians are not better qualified than lay people to make nutritional recommendations are nonsense. The best source of advice about pet diets is a veterinary nutritionist, and the second best source is your veterinarian.