Yes, Hydrangea is toxic to dogs!
Dogs accidentally consuming the Hydrangea 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).
Hydrangea consumption is also toxic to Cats and Horses.
Toxic Principles Of Hydrangea: Cyanogenic glycoside.
More Info About The Hydrangea Plant
Scientific Name: Hydrangea arborescens
Family: Hydrangeaceae.
Also known as: Hortensia, Hills of Snow, Seven Bark.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.
