Yes, Queensland Nut is toxic to dogs!
Dogs accidentally consuming the Queensland Nut 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).
More Info About The Queensland Nut Plant
Scientific Name: Macadamia integrifolia
Family: Proteaceae.
Also known as: Macadamia Nut, Australia Nut.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.