Food safety
Can dogs eat tomato?
Yes, but be careful
Ripe tomato flesh is fine in small amounts. Green tomatoes, leaves and stems aren't.
Being honest about this
Dogs differ, and amount matters — a crumb of something rich is not the same as half a packet. Treats of any kind should stay under a tenth of what your dog eats in a day. If you're unsure, your vet would far rather take the call.