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