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