Yes, Tomato Plant is toxic to dogs!
Dogs accidentally consuming the Tomato Plant plants can show the following clinical symptoms: Vomiting, Prolonged Depression, Incoordination, Hypersalivaton, Sleepiness Or Excitation, Dilated Pupils, Low Body Temperature, Low Blood Pressure, Coma, Seizure And Death (In Rare Cases).
Tomato Plant consumption is also toxic to Cats and Horses.
Toxic Principles Of Tomato Plant: Solanine.
More Info About The Tomato Plant Plant
Scientific Name: Lycopersicon spp
Family: Solanaceae.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.