Tomatoes

The leaves, stems and green fruit contain a harmful substance called tomatine. It decreases as the fruit ripens, so ripe tomatoes are not considered toxic.

Tomatoes in cat food are the ripe fruit, used dried or as part of a vegetable blend. Tomatoes belong to the nightshade family, and the green parts of the plant contain compounds that the ripe fruit has far less of. Pet foods use the ripe fruit. If your cat has a medical condition, ask your veterinarian about its food.

Tomatoes are added for fiber and lycopene, the red pigment in the fruit, and for a familiar vegetable name on the label. In dry cat food they appear in small amounts, often dried and ground. The Merck Veterinary Manual points out that animals require nutrients rather than particular ingredients, so tomatoes are optional in a complete recipe.

Source: merckvetmanual.com

Tomatoes means the fruit itself, while tomato pomace is what remains after tomatoes are processed for juice, sauce or paste. Pomace is mostly skins and seeds, so it is higher in fiber. The two are listed under different names, and Pettings treats them as separate ingredients.

No, cats have no known dietary requirement for lycopene. It is a red carotenoid pigment that acts as an antioxidant in lab tests. Cats cannot turn beta-carotene into vitamin A, according to the Merck Veterinary Manual, and lycopene is not a vitamin A source in any species.

Source: merckvetmanual.com

Pettings gives tomatoes 3 out of 5 and lists it as a fruit or vegetable ingredient. It appears on 5 of the 149 dry cat foods we list. The page notes that ripe tomatoes are not considered a concern for animals. Each food's page shows how it scores overall.