English ivy (Hedera helix) can be poisonous to dogs and cats. The toxin in ivy is the saponins it produces as a defense mechanism. The saponins in ivy act as emetine-like alkaloids, and can cause vomiting, abdominal pain, diarrhea, electrolyte imbalances, tachycardia, stupor, mydriasis (constricted pupils), and convulsions. If your pet ingests ivy, you should seek veterinary care as soon as possible.
What is English ivy?
The English ivy (Hedera helix) is a climbing plant in the araliaceous genus Hedera. In nature, this plant is known by many common names including ivy, ivy vine, English ivy, and English ivy vine. The English ivy belongs to the araliaceous subfamily and is native throughout much of Europe, North Africa, and Asia. This plant is widely cultivated as an ornamental and for its climbing properties.