Why
Tomatoes are a mixed case for cats. PetMD's veterinary guide states that ripe tomatoes are not toxic to cats, and PetMD's list of fruits that are safe for cats includes ripe tomatoes in small amounts. The same guide warns that the tomato plant and unripe fruit are not safe.
Tomato plants contain solanine, a compound that PetMD's guide describes as toxic to cats, dogs and horses. Solanine is found in the green leaves and stems, and PetMD's guide warns that unripe green tomatoes are not safe either. Even ripe tomatoes offer a cat little nutritional benefit, so PetMD's guide does not recommend them as a treat.
Risks to watch for
- Tomato leaves, stems and vines, including potted tomato plants on a balcony
- Unripe green tomatoes
- Tomato sauce, ketchup and tomato soup, which often contain onion, garlic, salt or sugar
- Tomato and egg stir-fry and other dishes cooked with scallions or onions
- Drooling, nausea or vomiting after chewing a tomato plant
- Lethargy or dilated pupils, which are an emergency
How to share safely
- Do not plan tomatoes into your cat's diet.
- If your cat insists on a taste, use only a tiny piece of plain, fully ripe red tomato flesh.
- Remove any green parts, including the small green cap.
- Keep tomato plants out of your cat's reach.
- If your cat chewed a tomato plant or ate unripe tomatoes, call your vet.
How much?
There is no recommended amount. PetMD's veterinary guide considers very small amounts of plain, ripe tomato safe but does not recommend tomatoes as a treat. All treats together should make up no more than 10 percent of a cat's daily calories.
Tomato plants and green tomatoes
Tomato plants are the real hazard for a cat. PetMD's veterinary guide explains that the leaves and stems contain solanine, and that eating even a small amount of the plant can cause signs of illness. Drooling, nausea and vomiting are usually the first signs, followed by loss of appetite, depression, lethargy, dilated pupils and a slowed heart rate.
Tomato poisoning is not normally fatal, according to PetMD's guide, but depression or dilated pupils are a medical emergency. Cats that like to chew greenery may be drawn to a pot of cherry tomatoes on a windowsill or balcony, so grow tomatoes where your cat cannot reach them.
Tomato sauce, ketchup and tomato dishes
Tomato sauce and tomato soup are cooked with ingredients that matter more than the tomato itself. PetMD's guide notes that they often contain oregano, garlic, onion, sugar or salt, and the Merck Veterinary Manual identifies garlic and onion as a cause of red blood cell damage in cats. A tiny lick of sauce is unlikely to cause harm, but these foods are best avoided.
Tomato and egg stir-fry, a comfort dish in many homes, is usually cooked with scallions and salt, and tomato beef soups and stews often contain onion. The same rule applies: if it was seasoned for people, it is not for the cat.
Cherry tomatoes and other fruit tomatoes
Cherry tomatoes are often eaten as fruit, and their size makes them easy for a cat to bat around and bite. A ripe red cherry tomato is the same as any ripe tomato: not toxic, but not recommended. A whole cherry tomato can also be awkward for a cat to swallow, so cut it up if your cat is determined to try it.
Cherry tomatoes that are still green, and the little green caps and stems, should be removed before any tomato is left where a cat can reach it. Those green parts are the ones PetMD's guide warns about.
Common questions
Are tomatoes good for cats?
Only in limited ways. Tomatoes are a mixed case for cats. PetMD's veterinary guide states that ripe tomatoes are not toxic to cats, and PetMD's list of fruits that are safe for cats includes ripe tomatoes in small amounts.
Are tomatoes bad for cats?
It can be. Risks to watch for: tomato leaves, stems and vines, including potted tomato plants on a balcony; unripe green tomatoes.
Are cats allowed to have tomatoes?
Only in small amounts and the right form. Do not plan tomatoes into your cat's diet.
My cat chewed on a tomato plant. What should I do?
Call your vet. PetMD's veterinary guide says that even a small amount of the tomato plant can cause signs such as drooling, nausea and vomiting. Do not try to make your cat vomit at home. Depression or dilated pupils need emergency care.
Is ketchup safe for cats?
Ketchup is not a good choice. Ketchup and tomato sauces usually contain sugar, salt and sometimes onion or garlic. A small lick is unlikely to cause harm, but do not share it.
Sources
- PetMD. Can Cats Eat Tomatoes? (Sandra C. Mitchell, DVM, DABVP)
- PetMD. What Fruits Can Cats Eat? 19 Fruits Safe for Cats (Teresa Manucy, DVM; reviewed by Sandra C. Mitchell, DVM, DABVP)
- Merck Veterinary Manual. Garlic and Onion (Allium spp) Toxicosis in Animals.
- ASPCA Animal Poison Control Center. People Foods to Avoid Feeding Your Pets.
- Cornell Feline Health Center. Feeding Your Cat.
If your cat has eaten something toxic, contact your veterinarian, an emergency animal hospital or an animal poison control service right away, even if your cat seems fine. Do not try to make your cat vomit at home.