Grain-free

Grain-free cat foods leave out cereals such as wheat, corn, barley and rice. They became popular alongside the idea that cats, as carnivores, should not eat grain. It is true that cats need little carbohydrate, see obligate carnivore, but cooked grains are digestible and not harmful to most cats.

Grain-free does not mean low-carb. Manufacturers usually replace the grain with potato, peas, lentils or tapioca, and some grain-free dry foods contain as much starch as ordinary ones. Check the guaranteed analysis and the ingredient list rather than the front of the pack. The label also says nothing on quality. A grain-free food must still be complete and balanced.

Food allergies in cats are more often caused by proteins such as beef, fish or chicken than by grains. If you suspect an allergy, with itchy skin or recurring stomach upsets, talk to your vet about a supervised trial, see limited-ingredient diet. Changing the food at random can hide the cause and delay a diagnosis.

If you choose a grain-free food, make sure it has the proper nutrition statement, and ask your vet about unusual diets, especially if the cat has heart or kidney disease.