Yes, Chinese Evergreen is toxic to dogs!
Dogs accidentally consuming the Chinese Evergreen 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).
Chinese Evergreen consumption is also toxic to Cats and Horses.
Toxic Principles Of Chinese Evergreen: Insoluble calcium oxalates.
More Info About The Chinese Evergreen Plant
Scientific Name: Aglaonema modestum
Family: Araceae.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.