If your dog ate green tomatoes, tomato leaves, or stems, the most important step is calling your veterinarian or an emergency animal poison hotline immediately. Ripe red tomatoes are safe for dogs in small amounts, but the green parts of the tomato plant contain compounds that can cause vomiting, lethargy, and in serious cases, kidney damage. How much your dog ate and which part of the plant they got into determines how urgent the situation is.
Which Parts of the Tomato Plant Are Toxic
The danger comes from a compound called tomatine, concentrated in the green, unripe portions of the plant. Green tomatoes contain roughly 16,000 micrograms of tomatine per gram of fresh fruit. That’s a substantial amount. Leaves and stems also contain tomatine, though at lower concentrations (around 1,500 to 1,800 micrograms per gram). Once a tomato fully ripens and turns red, tomatine drops to undetectable levels, which is why ripe tomatoes are considered safe for dogs.
The stems and leaves also contain oxalates, compounds that can contribute to bladder stones and, in large enough quantities, acute kidney failure. This makes the leafy green parts of the plant a double threat.
There’s no established toxic dose in milligrams per kilogram for dogs. Pet Poison Helpline notes that dogs would typically need to consume a significant amount of the toxic plant material to experience serious effects. But “significant” varies with your dog’s size. A small dog gnawing through a tomato plant in your garden faces more risk than a large breed eating a single green cherry tomato.
Symptoms to Watch For
The most common signs of tomato plant poisoning in dogs are gastrointestinal: vomiting, loss of appetite, and general lethargy. You may also notice your dog drinking and urinating more than usual, which can signal that the kidneys are under stress from the oxalates in the plant material. These symptoms can appear within a few hours of ingestion.
If your dog ate only a small piece of a green tomato or nibbled briefly on a leaf, you might see mild stomach upset that resolves on its own. Larger ingestions, especially of leaves and stems, carry the risk of more serious complications including kidney problems. The key distinction is whether your dog sampled the plant or made a meal of it.
What to Do Right Away
Call your veterinarian or a pet poison control center before doing anything else. When you call, have this information ready: what part of the plant your dog ate, roughly how much, when it happened, and your dog’s approximate weight. This helps the vet assess how critical the situation is and whether you need to come in immediately.
Do not try to make your dog vomit without veterinary guidance. Cornell University’s veterinary college warns that inducing vomiting is sometimes the wrong call depending on the substance, the timing, and the dog’s condition. Your vet will tell you whether home-induced vomiting is appropriate or whether you should head to the clinic instead. If the ingestion happened within the last one to two hours and the vet recommends it, they may walk you through the process over the phone or have you bring your dog in for supervised treatment.
How Veterinarians Treat It
Treatment for tomato plant poisoning is supportive, meaning there’s no specific antidote. The goal is to minimize absorption of the toxins and keep your dog stable while their body processes what they ate.
If your dog arrives at the clinic soon after ingestion, the vet may administer activated charcoal, which binds to toxins in the stomach and intestines to reduce how much gets absorbed into the bloodstream. This is sometimes combined with a substance called sorbitol that helps move everything through the digestive tract faster.
For more significant ingestions, the primary treatment is aggressive intravenous fluid therapy. IV fluids serve multiple purposes: they help flush the kidneys (which are vulnerable to the oxalates found in tomato plant stems and leaves), prevent dehydration from vomiting, and support overall organ function while the dog recovers. Your vet will likely monitor kidney values through blood work, especially if your dog ate a large amount of plant material.
What Recovery Looks Like
Most dogs that receive prompt treatment for tomato plant ingestion recover fully. Mild cases involving small amounts of green tomato or brief nibbling on a leaf often resolve with nothing more than a few hours of stomach upset. Dogs that ate larger quantities and needed veterinary intervention typically improve over 24 to 72 hours with fluid support, though your vet may want to recheck kidney function before giving the all-clear.
The prognosis depends largely on how much was eaten and how quickly treatment started. Kidney damage from oxalates is the most serious potential complication, but it generally requires a substantial ingestion to reach that point.
Ripe Tomatoes Are a Different Story
If your dog simply ate a ripe, red tomato off your counter, that’s not a poisoning situation. Ripe tomatoes contain no detectable tomatine and are considered non-toxic to dogs. The only concern with ripe tomatoes is their natural acidity, which can irritate the stomach in dogs with sensitive digestion or existing conditions like acid reflux or chronic gastritis. A few bites of ripe tomato as an occasional treat is perfectly fine for most dogs.
Tomato-based products like ketchup and pasta sauce are a separate concern. These often contain added salt, sugar, onion, garlic, or in some cases xylitol (an artificial sweetener that is highly toxic to dogs). Stick to plain ripe tomato if you want to share.
Preventing Repeat Incidents
If you grow tomatoes, fence off your garden or use raised beds that your dog can’t access. Dogs that spend unsupervised time near tomato plants are the most common victims, especially puppies that chew on anything within reach. Fallen green tomatoes are another hazard since they sit at nose level and contain the highest tomatine concentrations of any part of the plant. Pick up any dropped fruit promptly, and prune low-hanging branches your dog could reach.