Interesting still is that the calories were controlled in both the vegetarian diet and meat based diet so the caloric intake was equal. (nutritionfacts.org)
They need meat based diets, they do not do well on grain and cereal diets. (allfelinehospital.com)
That means they must eat a species - appropriate meat based diet, and senior cats in particular should be fed a cat food with a high - quality protein. (1800petmeds.com)