Can Dogs Eat Tomatoes?

Tomatoes are the food that gives dog owners the most contradictory advice, and there is a reason for that. The ripe red fruit and the rest of the tomato plant are not the same thing. The part people eat contains only trace amounts of the compounds that worry vets. The leaves, stems, and unripe green fruit contain much more of them.

So a dog who steals a piece of ripe tomato from a salad is usually fine. A dog who chews through the tomato vines in the garden is a different situation, and one worth a phone call.

Why the Tomato Plant Is the Problem

Tomatoes belong to the nightshade family, and like several of their relatives they produce glycoalkaloids as a defense against being eaten. The main one in tomato is α-tomatine, and it is concentrated in the leaves, stems, and immature green fruit. As a tomato ripens and turns red, the level drops to the point where the fruit is considered low-risk.

Dogs that eat a significant amount of green plant material can develop:

• Drooling and vomiting
• Diarrhea
• Lethargy and weakness
• Tremors
• Dilated pupils
• A slow or irregular heart rate, in serious cases

Severe cases are uncommon, but they happen most often with dogs who raid a vegetable garden, chew on potted tomato plants, or get into a compost pile. Puppies and small dogs reach a meaningful dose on much less plant material.

Ripe Tomato Flesh

A fully ripe red tomato, skin and flesh only, is generally considered safe for dogs in small amounts. It is not a food with any special benefit for them, though. There is no nutrient in a tomato that a dog cannot get from a complete diet, and the fruit is acidic enough that some dogs get an upset stomach from it.

Treat it as a small, occasional taste rather than a treat you go out of your way to offer. If your dog enjoys it and tolerates it, a piece now and then is fine.

Cherry Tomatoes and Other Varieties

Cherry tomatoes follow the same rule as larger ones: ripe and red is low-risk, green and unripe is not. Because they are bite-sized, many dogs swallow them whole, so cut them into halves or quarters, especially for a small dog. Remove the stem and the leafy top first.

Other varieties are no different. The color of the ripe fruit is what matters, not the size.

Why Tomato Products Are a Bad Idea

Sauce, ketchup, salsa, tomato soup, and pasta sauce are not simply tomato in another form. They usually contain onion and garlic, both of which are genuinely toxic to dogs, along with a great deal of salt, sugar, and oil. Onion and garlic are the bigger concern here, not the tomato.

Some products also contain xylitol or other sweeteners, which are dangerous in small amounts. A jar of sauce on a kitchen counter is a real hazard, more so than a tomato on the counter.

If Your Dog Ate Green Tomatoes or Tomato Plants

Call your veterinarian or a poison control service with an estimate of how much plant material was eaten and when. Do not wait for symptoms to develop, because treatment is easier before they do.

• ASPCA Animal Poison Control Center (US): (888) 426-4435 — a consultation fee may apply
• Pet Poison Helpline (US and Canada): (855) 764-7661

If the dog only ate a piece of fully ripe red tomato, there is usually no need for an emergency call. Watch for a day and call your vet if vomiting, diarrhea, or unusual tiredness appears.

How to Share a Tomato

If you want to give your dog a piece of ripe tomato, keep it simple:

1. Use only fruit that is fully red and ripe.
2. Cut away the stem, any leaves, and any green or pale unripe sections.
3. Cut the flesh into pieces small enough that your dog will not swallow them whole.
4. Keep the total to a small taste, within the 10% of daily calories that treats should occupy.
5. Leave out the salt, oil, dressing, and everything else.

Stop if your dog shows any stomach upset. Some dogs handle tomato without a problem, and others do not.