Can dogs eat tomatoes? Ripe, green, cherry and sauce

Yes, with care. Ripe red tomato flesh is generally tolerated by dogs in small amounts, plain. The green parts are the problem: unripe green tomatoes, stems, leaves and vines contain tomatine, which can make a dog ill. Tomato sauce is usually off the list too, because of the onion, garlic, salt and sugar that come with it.

Are tomatoes safe for dogs?

It depends on which part of the plant and what has been added to it.

What tomatine does

Tomatine is a natural defensive compound in the tomato plant. It is concentrated in the leaves, stems and unripe fruit, and falls to very low levels as the fruit ripens.

A dog usually has to eat a fair amount of plant material to be seriously affected, and severe cases are uncommon. Small dogs have less margin. Reported signs include drooling, vomiting, diarrhea, loss of appetite, tiredness, weakness, wobbliness, wide pupils and a slow heart rate. If you cannot tell whether a green tomato is unripe or a variety that stays green, treat it as unripe.

Can dogs eat cherry tomatoes?

Ripe cherry tomatoes are treated the same as any ripe tomato: a little, plain, with the green stem and leafy cap removed. Cut them in halves or quarters first. A whole cherry tomato is round, firm and slippery, which makes it a choking risk for small dogs and for dogs that swallow without chewing.

Grape tomatoes are tomatoes, so the same applies. Actual grapes are a different matter and are never safe. See why dogs cannot eat grapes or raisins.

Can dogs eat tomato sauce?

No, not as a rule. The tomato is the least of it. Most pasta sauces, pizza sauces, soups and salsas contain onion and garlic, which are toxic to dogs and damage red blood cells. Powdered onion and garlic count, and they are easy to miss on a label.

Sauces are also salty, often sugary and sometimes oily. Ketchup has the same problems in a smaller serving. Check any sugar-free product for xylitol, also labeled birch sugar, which is dangerous to dogs.

If your dog licked a plate, the risk depends on the recipe, the amount and the size of your dog. Keep the jar or the recipe and call your vet for advice. Signs of onion or garlic poisoning can take several days to show, so a dog that looks fine that evening is not necessarily in the clear.

How to offer tomato safely

• Choose a fully ripe, red tomato. Wash it and remove the stem, leaves and any green patches.
• Serve it plain. No salt, oil, dressing or seasoning.
• Cut it into small pieces to suit your dog.
• Start with one small piece and watch for a day for vomiting, loose stools or itching.
• Keep it occasional. Treats of all kinds should stay a small part of the day's food, commonly put at about a tenth of daily calories.

If you grow tomatoes, the plants are a bigger risk than the fruit. Fence the bed or keep pots out of reach, and clear away prunings and fallen green fruit.

Tomatoes and older dogs

Tomatoes are acidic. Many older dogs have more sensitive stomachs than they used to, and some have reflux: lip licking, gulping, burping, or bringing up food or yellow fluid, often overnight or early in the morning. Acidic foods can make that worse. If your dog already has an unsettled stomach, skip tomato. Our article on why an old dog vomits goes through the other causes.

Ask your vet before offering tomato if your dog:

• Has a sensitive stomach, reflux or a history of pancreatitis
• Is on a prescription diet, for example for kidney disease, bladder stones or food allergies, where extras can undo the diet
• Takes medicine that can irritate the stomach, such as prescribed anti-inflammatory pain relief
• Has diabetes or is on a weight-loss plan, where every treat needs to be counted

Tomato adds nothing a complete dog food does not already provide. The main diet matters far more: see what to look for in a senior dog food and our senior pet nutrition guide.

When to call the vet today

Call your vet, an emergency clinic or an animal poison control line now if your dog:

• Has chewed or eaten tomato leaves, stems or vines, or unripe green tomatoes
• Has eaten sauce, soup or another food containing onion, garlic, chives, leeks or xylitol
• Is vomiting repeatedly, has diarrhea that will not settle, or has blood in either
• Is drooling heavily, weak, wobbly, trembling or unusually sleepy
• Has pale gums, fast breathing or dark urine in the days after eating onion or garlic
• Is choking, gagging or struggling to breathe after swallowing a whole tomato

This article is general educational information about tomatoes and dogs, not veterinary advice. How a dog reacts depends on its size, health, diet and medicines, and on exactly what was eaten. If your dog has eaten tomato plant, green tomatoes or a sauce with onion or garlic, or you are unsure whether tomato suits your dog, ask your veterinarian.