Yes, Cannabis is toxic to dogs!
Dogs accidentally consuming the Cannabis 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).
Cannabis consumption is also toxic to Cats and Horses.
Toxic Principles Of Cannabis: Delta-9-THC (tetrahydrocannabinol).
More Info About The Cannabis Plant
Scientific Name: Cannabis sativa
Family: Cannabaceae.
Also known as: Marijuana, Indian Hemp, Hashish.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.