Are Tomato Leaves Dangerous for Cats & Dogs?

Keep pets out of your tomato garden for their safety.
i tomato plant image by Crisps85 from

Your curious kitty or pup may want to snack on your tomato plants, either grown indoors or in your outdoor garden. Tomato plants can be toxic to both cats and dogs. Keep your pets away from these plants, especially the leaves and stems, which contain most of the toxins.

The Tomato Plant

The tomato plant is also known as the Lycopersicon spp. and is in the Solanaceae family of plants, the same family as deadly nightshade. The green parts of the plant, including the leaves and stems, contain ingredients called glycoalkaloids, which are toxic to cats and dogs if ingested. While green tomatoes also contain this chemical, ripe tomatoes don't, according to the American Society for the Prevention of Cruelty to Animals. Eating ripe tomatoes might only cause a little gastrointestinal upset if eaten by your pets. Cooked, ripe tomatoes are also safe, making tomato sauces OK for your furry friends.

Possible Reactions

The leaves of a tomato plant contain the glycoalkaloids alpha-tomatine and dehydrotomatine, according to the Health Canada website. These substances are toxic to both pets and people. If your cat or dog eats the leaves, he might experience lethargy, drooling, stomach upset, diarrhea, vomiting and changes in his behavior, the ASPCA warns. Tremors or seizures could also occur, according to VetInfo. If you have observed or suspect your kitty or pup has munched on your tomato plants, it's best to get him to the vet so he can be treated. Poisoning is a serious situation and you should visit an emergency vet if your regular vet isn't available.

Restricting Access

Keep your cat and dog away from your tomato plants. Pets are curious and sometimes like to snack on their green leaves. If growing the plants indoors, place them in a room that your pet doesn't have access too, like a spare bedroom. For gardens containing tomato plants, contain them with fences or screens that your pet can't jump over or push aside. You can use other pet deterrents like motion-sensing sprinklers to scare your furbabies away from the garden. Other motion-activated devices emit an ultrasonic noise, which pets can hear but people can't, to keep your little ones away from potentially toxic garden plants, including tomato plants.


Never let your cat or dog eat the green parts of a tomato plant, including the leaves, stems or unripe fruit, because these are toxic to them. While ripe tomatoes are safe for pets, they shouldn't be eaten by those who have been diagnosed with calcium oxalate bladder or kidney stones, according to the Bichon Frise Club of America. Ripe, uncooked tomatoes may cause some mild tummy upset for your pet, so it's best to avoid giving them to your cat or dog at all. Give your kitties and pups some safe plants, like barley grass, to chew on, while restricting their access to potentially toxic plants like tomatoes.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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