Yes, Fetterbush is toxic to dogs!
Dogs accidentally consuming the Fetterbush 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).
Fetterbush consumption is also toxic to Cats and Horses.
Toxic Principles Of Fetterbush: Grayanotoxins.
More Info About The Fetterbush Plant
Scientific Name: Lyonia spp.
Family: Ericaceae.
Also known as: Staggerberry, Maleberry.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.