The answer is nuanced: ripe, red tomato flesh in small amounts is generally safe for dogs, but green tomatoes, tomato leaves, and tomato stems are toxic.
Ripe red flesh is okay — green parts are toxic
Ripe tomato flesh contains only trace amounts of tomatine (low enough to be safe). Green tomatoes, stems, and leaves are high in solanine and tomatine — compounds that are toxic to dogs. Never give your dog unripe tomatoes or any part of the tomato plant other than ripe flesh.
What makes tomatoes potentially toxic to dogs?
Tomatoes belong to the nightshade family and contain two toxic compounds in their green parts: solanine and tomatine. These are concentrated in the stems, leaves, and unripe (green) fruit. As a tomato ripens and turns red, these compounds break down significantly. Ripe red tomato flesh contains very low levels that are unlikely to cause problems in small amounts.
Can dogs eat tomato sauce?
Most commercial tomato sauces, ketchup, and marinara contain garlic and onion — both toxic to dogs — along with high salt, sugar, and other spices. Avoid giving dogs any tomato-based condiment or sauce.
How to safely give tomatoes to dogs
- Use only fully ripe, red tomatoes — no green sections.
- Remove the stem, leaves, and green parts completely.
- Give only the flesh in small pieces — no more than 1–2 cherry tomatoes for a medium dog.
- Plain only — no salt, no seasoning, no sauce.
