Yes, Yesterday, Today, Tomorrow is toxic to dogs!
Dogs accidentally consuming the Yesterday, Today, Tomorrow 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).
Yesterday, Today, Tomorrow consumption is also toxic to Cats and Horses.
Toxic Principles Of Yesterday, Today, Tomorrow: Brunfelsamidine.
More Info About The Yesterday, Today, Tomorrow Plant
Scientific Name: Brunfelsia species
Family: Solanaceae.
Also known as: Morning-Noon-and-Night, Kiss-Me-Quick, Lady-of-the-Night, Fransiscan Rain Tree, Brunfelsia.
The answer is based on information found on The American Society for the Prevention of Cruelty to Animals (ASPCA) website.