Why?
Ripe red tomatoes in small amounts are generally safe. However, the stems, leaves, and unripe green tomatoes contain solanine and tomatine — glycoalkaloids that are toxic to dogs.
How much can dogs have?
A piece or two of ripe red tomato flesh as an occasional treat.
What to watch out for
Never let dogs chew tomato plants or unripe tomatoes. Solanine poisoning causes weakness, gastrointestinal issues, and cardiac effects.