Can Cats Eat Tomatoes?

CONDITIONAL: Ripe tomato flesh in very small amounts is not especially toxic, but green parts and processed tomato products can be dangerous—most vets advise avoiding tomatoes entirely.

Quick Safety Summary

Quick Safety Summary: CONDITIONAL — Ripe, fully red tomato flesh may be offered as a very small, infrequent treat (a few grams) but offers no nutritional need for cats. All green parts of the tomato plant (leaves, stems, unripe green tomatoes) and tomato-based processed foods (ketchup, sauces, salsa) can be toxic because of solanine and other ingredients. If your cat eats leaves, stems, green tomatoes, or a large amount of tomato product, call your veterinarian or ASPCA Animal Poison Control immediately (888-426-4435).

CONDITIONAL: Cats can eat very small amounts of ripe tomato flesh, but green tomato plant parts and processed tomato products are potentially toxic and should be avoided.

Why this answer is conditional

• Ripe, red tomato flesh is low in toxicity and is not a natural part of an obligate carnivore’s diet; a few small bites are unlikely to cause harm.
• Green tomato parts (leaves, stems, unripe fruit) contain glycoalkaloids — chiefly solanine — which can cause gastrointestinal and neurologic signs in cats.
• Processed tomato products (ketchup, pasta sauce, salsa) often contain salt, sugar, onion/garlic, and spices that increase risk and can be toxic.

Tomatoes are mostly water and provide negligible calories and protein compared with meat. Per 100 g raw tomato (USDA FoodData Central approximate values):

• Calories: ~18 kcal
• Water: ~94–95 g
• Protein: ~0.9 g
• Fat: ~0.2 g
• Carbohydrates: ~3.9 g (sugars ~2.6 g, fiber ~1.2 g)
• Vitamin C: ~10–14 mg
• Potassium: ~230–250 mg
• Lycopene and other antioxidants (bioactive plant compounds)

H2: Toxicology — why green parts and unripe tomatoes are risky

H3: Solanine and other glycoalkaloids

Tomatoes belong to the nightshade family (Solanaceae). Green parts of tomato plants—leaves, stems and unripe green fruit—contain glycoalkaloids such as solanine and tomatine. These compounds are natural plant defenses and can be toxic to mammals in sufficient amounts.

Clinical signs of solanine (glycoalkaloid) exposure in cats can include:

• Drooling, nausea, vomiting, diarrhea
• Abdominal pain and loss of appetite
• Lethargy, weakness, incoordination (ataxia)
• Dilated pupils, hypersalivation
• Rapid heart rate or changes in breathing in severe cases

Sources: ASPCA Animal Poison Control, Merck Veterinary Manual, veterinary toxicology texts.

H3: Processed tomato products bring additional hazards

Ketchup, pasta sauces, salsa and canned tomatoes may contain: high salt, sugar, onion/garlic powder, spices, or added fats. Of these, onion and garlic (Allium species) are particularly hazardous for cats — they can cause oxidative damage to red blood cells leading to hemolytic anemia even in small doses over time. High salt or sugar content is also undesirable and may cause gastrointestinal upset or contribute to other health problems.

H2: Practical recommendations for pet owners

H3: If you choose to offer tomato

• Only give small amounts of fully ripe, red tomato flesh (no green bits, no leaves/stems).
• Serving size guidance by weight (conservative):

• Frequency: occasional only — once every few weeks at most.
• Preparation: wash thoroughly, remove skin if you like (most concern is plant tissue), serve plain and cool.
• Monitoring: watch for vomiting, drooling, lethargy, or changes in behavior for 24 hours after offering.

H3: What to avoid entirely

• Tomato leaves, stems, and unripe (green) tomatoes — these are toxic and should not be accessible to cats.
• All tomato-based processed foods (ketchup, pizza/cooking sauces, canned soup, salsa) — avoid due to added ingredients that can be toxic or unhealthy.
• Dried tomato products or tomato powders — concentrations and added ingredients make them unsuitable.

Most veterinarians recommend avoiding feeding tomatoes to cats for these reasons:

• The nutritional benefit is negligible for an obligate carnivore; tomatoes do not supply required amino acids (like taurine) or fats cats need.
• There is a non-zero risk of toxic exposure from plant glycoalkaloids if green parts or unripe fruit are ingested.
• Processed tomato products often contain other harmful ingredients (onion, garlic, excess salt/sugar).
• Simplicity: advising owners to keep all human nightshade foods away from pets reduces accidental poisonings and confusion.

If your cat ate tomato leaves, stems, unripe fruit, or a large quantity of tomato-based product, act quickly:

Emergency signs that need immediate veterinary attention: repeated vomiting, severe lethargy, tremors or seizures, difficulty breathing, collapse, or signs of hemolytic anemia (weakness, pale gums, rapid breathing) after exposure to tomato-based foods that contained onion/garlic.

H2: Real-world risk — how common is tomato poisoning in cats?

Isolated cases are reported when cats chew on garden plants or eat significant quantities of tomato plant matter. Most exposures to small amounts of ripe tomato flesh result in no clinical signs. More serious cases tend to involve ingestion of substantial amounts of plant material (leaves/stems/green fruit) or processed foods containing other toxic ingredients.

H2: Alternatives and safe treats for cats

If you want to offer something novel to your cat, consider safer options that provide sensory variety without the risks: small pieces of cooked plain chicken, turkey, or a commercial cat treat formulated for feline nutrition. If you favor vegetables, tiny amounts of plain cooked pumpkin or steamed carrot are safer choices for occasional tasting — but these still should be a very small percentage of total calories.

H2: Final verdict

CONDITIONAL — A tiny nibble of fully ripe red tomato flesh is unlikely to harm most cats, but tomatoes provide no meaningful nutrition for an obligate carnivore and carry real risk if green parts or processed products are consumed. For simplicity and safety most veterinarians advise keeping tomatoes and all nightshade plant parts out of your cat’s reach.

Key Takeaways

• Ripe red tomato flesh: low-risk in very small amounts but unnecessary nutritionally.
• Green parts (leaves, stems, unripe tomatoes): contain solanine and tomatine and can cause GI and neurologic signs — potentially toxic.
• Tomato-based processed foods (ketchup, sauce, salsa): avoid — may contain onion/garlic, salt, sugar and spices harmful to cats.
• If your cat eats green tomato parts or shows signs of poisoning, call your vet or ASPCA Animal Poison Control (888-426-4435) immediately; do not induce vomiting without veterinary advice.

• ASPCA Animal Poison Control Center, “Tomato” (plant) information: https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/tomato
• Merck Veterinary Manual, Plant Poisoning and Toxicology sections: https://www.merckvetmanual.com/toxicology
• American Veterinary Medical Association (AVMA) general pet food and toxicology resources: https://www.avma.org

Frequently Asked Questions