With more and more people using essential oils to enhance their own well being, it is also spreading into veterinary medicine. Unfortunately, most essential oils are toxic to dogs and cats. People who use them for treating or training their pets may, in fact, be unintentionally harming them instead.
Birch Oil: Birch oil is often used for scent training dogs. Researchers at Michigan State University, College of Veterinary Medicine found that birch oil contains toxic amounts of methyl salicylate. If a dog comes into contact with undiluted birch oil, it can cause severe gastrointestinal ulcers, kidney failure, seizures and death. In addition to this direct poisoning, the smell of birch oil, anise or clove may lead to secondary poisoning from xylitol. Dr. Cheryl Swenson and colleagues found scent trained dogs may confuse the birch oil, anise or clove scent with the wintergreen scent used in many sugar-free products. Most of these products contain xylitol which is safe in people but harmful to dogs and cats.
Tea Tree (Melaleuca) Oil: In the last five years, I am seeing an increase in the number of animals poisoned with tea tree oil. According to the Pet Poison Helpline, “as little as 7 drops of the 100% oil has resulted in severe poisoning.” The owner brings their dog or cat in for lethargy and problems walking. During the physical examination, I find an oily substance on their skin or in their ears. The animals also have a low body temperature. They look like a drunk human! In mild cases, the animals will perk up within 24 hours of removing the oil from their skin. Unfortunately, even with supportive care some animals will slip into a coma and die.
Other Essential Oils: In practice, I have seen dogs and cats with severe skin damage from essential oils. In mild cases, the oil burns the skin causing inflammation. In severe cases, layers of skin slough off causing deep ulcers. The poor animal licks it off causing a secondary burn to their mouth. I saw a cat who sloughed the entire top of her tongue from essential oils. Her owner used undiluted oil as a treatment for ear mites. The insides of her ears were a bloody mess. With intensive care, the cat survived but was deaf for the rest of her life.
-Veterinary toxicology alert: Oils used in ‘scent training’ can harm dogs., DVM360, March 17, 2014.