Unripe (green) tomatoes and the tomato plant itself contain higher concentrations of solanine and tomatine, alkaloids in the nightshade (Solanaceae) family. These compounds can cause gastrointestinal upset, hypersalivation, appetite loss, a slowed heart rate, and depression. Ripe, red tomato flesh is generally considered non-toxic, with risk concentrated in the green, unripe fruit and the plant's leaves and stems. Some sources note cats may react more sensitively to solanine than dogs, related to more limited liver detoxification capacity.
No specific safe threshold is established. Because the plant and unripe fruit carry the actual risk while ripe fruit is generally considered safe, avoid green tomatoes and tomato plant material specifically rather than tomatoes as a whole category.
No — ripe, red tomato flesh is generally considered non-toxic to cats. The risk is concentrated in green, unripe tomatoes and in the plant's leaves and stems, which contain much higher levels of the alkaloid solanine.
Remove any remaining plant material and call a veterinarian or pet poison hotline for advice, particularly if the cat ate leaves, stems, or unripe fruit. Watch for drooling, vomiting, lethargy, or unusual behavior and report any signs.
The leaves, stems, and unripe fruit are the parts of concern. Keeping plants fenced off or out of reach is the simplest precaution, and ripe red fruit that falls to the ground should be picked up promptly.
General public resources referenced while researching this tool's topic.
General educational guidance based on the references above, not veterinary advice. See our editorial policy for how we choose sources.
This tool is intended for educational purposes only and should not be used as a substitute for emergency veterinary advice, diagnosis, or treatment.
If your pet may have consumed toxic foods, chocolate, medications, chemicals, or other dangerous substances, seek immediate help from a licensed veterinarian or emergency animal service in your area. Do not delay professional care based on calculator or search results alone.
Pet poison hotlines (24/7, US and Canada):
ASPCA Animal Poison Control Center: (888) 426-4435
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Pet Poison Helpline: (855) 764-7661
Pet Poison Helpline states its service covers the U.S., Canada and the Caribbean. The ASPCA line is also used by Canadian pet owners. A consultation fee may apply to both. In Canada, your nearest 24-hour emergency vet clinic is the best first call; elsewhere, use local emergency veterinary directories.
How we calculate results: This tool uses commonly referenced veterinary toxicity thresholds and food safety guidelines. Actual toxicity can vary based on your pet's size, health status, and exact substance consumed. These results are estimates only and do not replace a veterinary assessment.