Yes, Indian Hemp is toxic to dogs!
Dogs accidentally consuming the Indian Hemp 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).
Indian Hemp consumption is also toxic to Cats and Horses.
Toxic Principles Of Indian Hemp: Cardenolides.
More Info About The Indian Hemp Plant
Scientific Name: Apocynum androsaemifolium
Family: Apocynaceae.
Also known as: Dogbane Hemp, Bitter Root.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.