Yes, Cordatum is toxic to dogs!
Dogs accidentally consuming the Cordatum 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).
Cordatum consumption is also toxic to Cats and Horses.
Toxic Principles Of Cordatum: Insoluble calcium oxalates.
More Info About The Cordatum Plant
Scientific Name: Philodendron oxycardium
Family: Araceae.
Also known as: Fiddle-Leaf, Horsehead Philodendron, Heartleaf Philodendron, Panda Plant, Split Leaf Philodendron, Fruit Salad Plant, Red Emerald, Red Princess, Saddle Leaf.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.