Sap from stems can cause inflammation and blistering on skin or mucous membranes and even around the hooves of horses used to harvest. There is no known antidote for the poison ranunculin found in the buttercup varieties. Efforts should be concentrated on prevention through pasture management. A veterinarian should be consulted immediately for supportive treatment to reduce the damage caused by ingestion of poisonous plants. Yew poisoning is the commonest form of animal poisoning.
Yew contains an alkyloid that depresses the action of the heart.
Yew needles are greenish-yellow on the under surface and have no white stripes. A veterinarian should be consulted immediately for supportive treatment to reduce the damage caused by ingestion of poisonous plants. Its flowers are show and very fragrant, but the belief that their perfume is dangerous is unfounded. Oleander ranks with yew in toxicity. Oleander contains a poisonous principle similar to digitalis in its effect on the heart, causing arrhythmia and cardiac arrest.