Why
Tomatoes belong to the nightshade family. The green parts of the plant, including stems, leaves and unripe fruit, contain solanine and tomatine, which can cause stomach upset and other problems if eaten in larger amounts.
Ripe tomatoes contain very little of these compounds. The bigger risk is often what comes with them: tomato sauces, soups and ketchup frequently contain onion, garlic, salt and sugar. If you grow tomatoes, keep your dog away from the plants.
Risks to watch for
- Vomiting or diarrhea
- Drooling
- Lethargy or weakness after eating tomato plants
- Onion or garlic in sauces and soups
How to share safely
- Offer small pieces of ripe, washed tomato.
- Skip sauces, soups, pizza and ketchup.
- Fence off tomato plants in the garden.
How much?
A dog can have a few small pieces of tomato occasionally.
What if my dog chewed the tomato plant?
The ASPCA lists the tomato plant as toxic to dogs. Leaves and stems can cause drooling, loss of appetite, stomach upset and diarrhea. With larger amounts, dogs may become drowsy, weak or confused, with dilated pupils or a slow heart rate. Serious cases are uncommon because the plant is bitter, but they happen.
Take a photo of the plant and estimate how much is missing, then call your vet. Also check what else was in the bed. Snail and slug baits containing metaldehyde can cause severe tremors in dogs, and many fertilizers and garden sprays cause vomiting on their own.
Ketchup, salsa and pizza sauce
Most tomato products are a bigger worry than tomatoes. Many contain onion or garlic, which damage a dog's red blood cells. That damage can take several days to show as weakness, pale gums or dark urine.
If your dog ate a sauce that contains onion or garlic, call your vet or a poison control line and say roughly how much. A dog that emptied a pot of pasta sauce or ate a pile of salsa should be seen by a vet, even if it seems fine.
- Salsa often adds raw onion and hot peppers, which irritate the stomach.
- Sun-dried tomatoes in oil are salty and fatty.
- Sugar-free ketchups and sauces should be checked for xylitol.
- Tomato soup often has onion powder and cream, so treat it like a sauce.
Are cherry tomatoes and green tomatoes different?
Ripe cherry tomatoes are fine in the same small amounts as large tomatoes. Cut them in half for small dogs, because a whole one is the right size and slipperiness to lodge in the throat.
Green, unripe tomatoes that drop off the vine carry more solanine than ripe ones. Pick them up before your dog does, especially late in the season when frost stops them ripening. Green potatoes and potato sprouts contain solanine as well, so keep raw potato peelings out of reach.
Common questions
Are tomatoes good for dogs?
Only in limited ways. Tomatoes belong to the nightshade family. The green parts of the plant, including stems, leaves and unripe fruit, contain solanine and tomatine, which can cause stomach upset and other problems if eaten in larger amounts.
Are tomatoes bad for dogs?
It can be. Risks to watch for: vomiting or diarrhea and drooling.
Are dogs allowed to have tomatoes?
Only in small amounts and the right form. Offer small pieces of ripe, washed tomato.
Sources
Topic references
- ASPCA Animal Poison Control Center. Toxic and Non-Toxic Plant List – Dogs.
General care and safety
If your dog has eaten something toxic, contact your veterinarian or an emergency animal hospital right away. Do not wait for symptoms. In the US you can also call the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661 (fees may apply).