Poor coat quality can be caused by a number of nutritional inadequacies, and suggests low diet quality. Cost per day rather than cost per container should be determined, because of the differences in diet quality and energy density. The FDA requires drugs, but not foods to demonstrate safety and efficacy.
Clinicians have a daily opportunity to evaluate the quality of diets.
One should recommend those with which one has had positive experiences and against diets when a pattern of inadequacy is discerned. Moreover, absence of a product from one's list does not mean that it is unacceptable, only that insufficient experience with it has been obtained. If so, it means that the manufacturer was sufficiently concerned with the quality of their product to feed it to animals before offering it for sale. The majority of urban pets are inactive, neutered adults. The nutrient needs of these animals are not great, but may need to be provided in the small volume of food needed to maintain moderate body condition.