Yes, Privet is toxic to dogs!
Dogs accidentally consuming the Privet 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).
Privet consumption is also toxic to Cats and Horses.
Toxic Principles Of Privet: Terpenoid glycosides.
More Info About The Privet Plant
Scientific Name: Ligustrum japonicum
Family: Oleaceae.
Also known as: amur, wax-leaf, common privet.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.