Yes, Clematis is toxic to dogs!
Dogs accidentally consuming the Clematis 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).
Clematis consumption is also toxic to Cats and Horses.
Toxic Principles Of Clematis: Irritant glycoside (Protoanemonin).
More Info About The Clematis Plant
Scientific Name: Clematis spp.
Family: Ranunculaceae.
Also known as: Virgin’s Bower, Leatherflower.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.