Is tea tree oil safe for dogs?

Tea tree oil is not safe for use in dogs. High concentrations of the oil are extremely toxic to dogs, and can cause lack of coordination, muscle weakness, trembling and coma.

The active ingredients in tea tree oil are terpenes. These anti-microbal compounds also have a negative, and even fatal effect on dogs. Tea tree oil, although frequently used to treat skin conditions in humans, is known to be poisonous to people if taken orally. Most human beings would never think to consume tea tree oil in this way, but dogs ease skin irritation by licking and biting the affected area. Accidental ingestion is much more dangerous to cats than to dogs, but dogs are nonetheless affected. If tea tree oil is to be used at all, it should be highly diluted to 1 percent concentration or less.