Yes, Heavenly Bamboo is toxic to dogs!
Dogs accidentally consuming the Heavenly Bamboo 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).
Heavenly Bamboo consumption is also toxic to Cats and Horses.
Toxic Principles Of Heavenly Bamboo: Cyanogenic glycosides.
More Info About The Heavenly Bamboo Plant
Scientific Name: Nandina domestica
Family: Berberidaceae.
Also known as: Sacred Bamboo, Nandina.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.