Tomato plants are toxic to cats, but the ripe tomato fruit itself is not. The toxic parts of the tomato plant include the leaves, stems, and unripe green tomatoes, which contain a chemical called solanine (also known as tomatine in tomato plants). When cats ingest these parts, they can experience symptoms such as hypersalivation, lack of appetite, gastrointestinal upset, weakness, slowed heart rate, and dilated pupils. If a cat eats tomato plant parts and shows any signs of toxicity, immediate veterinary attention is recommended. Ripe tomatoes are safe for cats in small amounts but are generally not recommended in their diet as cats are obligate carnivores.
