Carbohydrates and Cats

Cats are carnivores, which means they have evolved to eat meat. They have claws and sharp teeth for hunting and catching their prey. However, this is not to say that a complete cat food should not have carbohydrates included.

Cats were originally domesticated in Egypt where they were used in granaries for vermin control. The stomach of their prey (mice and rats) would contain partially digested grains. Cooking grains at a high temperature mimics the action of the stomach, therefore an extruded cat food should contain easily digested carbohydrates.

It is also important to note that pet cats are not the same as wild cats. Pet cats do not need as much energy from their diet. They are kept in centrally heated houses, they do not have to hunt for food and have been fed on ‘left-overs’ of human diets which will be cooked food (they would eat raw food in the wild), including meat and carbohydrates (whether they are from grains, cheese, milk or other sources). Even feeding your cat a raw food diet will not be equal to a diet in the wild. The food is not freshly killed, the meat will not be at body temperature and the organs and contents of organs will be missing.

Looking at the recent evolution of cats and their anatomy and physiology, we can see several adaptations which allow them to successfully digest carbohydrates:

• Kittens naturally eat carbohydrates. They ingest lactose (the sugar found in milk) from their mother.
• The pancreas of a cat secretes the enzyme Amylase. Amylase is used to break down carbohydrates (starch). If cats could not eat carbohydrates then they would not have the ability to produce amylase.
• The intestinal length of a carnivore (cat) is much shorter than that of an omnivore (e.g. dog) because of the way food is metabolised. However, domestic cats have been shown to have a longer intestinal tract than wild cats, thus proving dietary evolution. Source: ‘You & Your Cat’ By David Taylor BVMS, FRCVS. 1986.

The 4th Edition of ‘Small Animal Clinical Nutrition’ By Hand, Thatcher, Remillard and Roudebush. 2000.
‘Dry foods containing 40% or more dietary carbohydrates with an average digestibility of 85% are well tolerated by cats.’

‘Although no requirement for dietary carbohydrates has been demonstrated for adult cats, carbohydrates are a good source of energy and appear necessary for adequate lactation in queens.’

‘Strombeck’s Small Animal Gastroenterology’3rd Edition. Guilford, Center, Strombeck, Williams and Meyer. 1996.
‘It is perhaps surprising that cats can efficiently digest carbohydrate considering the low carbohydrate of their ancestral diet.’

There is also a huge difference between simple carbohydrates and complex carbohydrates. Simple carbohydrates are the ones more likely to cause diabetes and weight gain.

Complex carbohydrates can be divided in to two groups: (1) digestible ones, known as starch and (b) indigestible ones, known as fibre.

Digestion of complex carbohydrates takes longer than simple carbohydrates. This means that there is a slow absorption of food and thus a steady supply of energy rather than sudden sugar surges that you can get from simple carbohydrates. Rapid absorption of sugar also increases the likelihood that it will be converted in to body fat.

The starch available in cooked and extruded pet foods are easily digested. The extrusion process (cooking with heat and pressure) increases the digestibility of starch by causing it to gelatinize (canning food also does this).

The reason we use brown rice as the main ingredient in our cat food is to keep the protein and fat quantity at controlled levels. Although cats need higher amounts of protein and fat than dogs, excess dietary fat and protein may cause health problems.