We hear a lot about the cat being a ‘strict carnivore’ (obligate carnivore) but what does it mean in practical terms to the person looking after their cat? I’d like to explore that briefly in this article. The domestic cat is said to have “nutritional idiosyncrasies”. In other words a cat’s diet is idiosyncratic or very specialised compared to dogs for instance. This is because the cat’s wild ancestor (Near Eastern wildcat) feeds almost entirely on small animals such as mice and voles. We are compelled, therefore, as cat guardians, to replicate that wild diet.
The cat’s evolution has resulted in the animal developing physiological and metabolic adaptations resulting in this specialist diet. In terms of a person feeding a domestic cat it places demands which wouldn’t be in place if they had a dog companion. Some of these dietary requirements have a greater practical importance than others.
A cat requires animal tissues in their diet because of their requirement for a higher protein diet and their need for taurine, arachidonic acid and preformed vitamin A.
Compared to other animals, kittens and adult cats have an unusually high dietary protein requirement. This is significant on a practical basis because cats cannot adapt to a low-protein diet. They can’t maintain good health if they are on a fairly low-protein diet or companion animal commercially prepared foods formulated for dogs.
This is a fatty acid for which a cat has a dietary requirement because they don’t have the ability to synthesise adequate levels of it from linoleic acid.
Cats have a low synthesis of taurine in their body and they have a high demand for it and therefore it has to be added in the form of animal tissues. If a domestic cat is given food that contains only plant products a deficiency in taurine may result unless supplemented. Why is taurine important for cats?
Dogs and most other animals can synthesise vitamin A from beta-carotene but cats cannot. Animal tissues contain vitamin A (retinoic acid). Once again for cats plant-based products will result in a deficiency of Vitamin A.
Dogs and most other animals can convert the amino acid tryptophan to niacin which meets a part of their daily requirement but cats can’t do it. Niacin is therefore added to commercially prepared cat foods to avoid a practical deficiency.
Cats have a lack of essential enzymes and deficiencies resulting in an inability to produce and transport arginine precursors (the substances from which arginine is created) unlike many animals. Although an arginine deficiency in cats is not a practical problem. Arginine Is Critically Important For Cats
There is no dietary requirement in cats for carbohydrate as a source of glucose because cats are able to produce glucose through metabolic processes (gluconeogenesis) and due the “novel metabolic pathway for synthesis of glucose”. Therefore there is no practical significance for a lack of carbohydrate in the diet. Most cats consume some level of digestible carbohydrate. Manufacturers of Grainless Cat Foods Continue to add Carbohydrates for Obligate Carnivores
Note: the quote and information comes from MikeB and Linda P Case in her book: The Cat, It’s Behavior, Nutrition & Health.