Essential oils can be a wonderful natural way to treat your pet, but only when used appropriately. Undiluted 100% essential oils can have powerful, and many times unwanted affects on your dog or cat. Never use an essential oil that hasn’t been diluted without first contacting a veterinarian. The following paragraphs cover the most commonly used essential oils that can be harmful to our furry friends.
Riley, fully recovered from tea tree oil exposure
This is Riley, he came in to see me on Friday after having 100% Australian tea tree oil (Melaleuca oil) applied to his back on Thursday night. Tea tree oil is often found in shampoos and other skin treatments as flea repellant and for itching. Riley soon became nauseous and developed a problem with his hind legs where he was no longer able to walk. This is a typical toxic side effect of this oil, and it can also cause low blood pressure, low body temperature, dehydration, nervousness, tremors, seizures, coma, liver problems, and electrolyte abnormalities. Fortunately for Riley, a bath in Dawn dish detergent and some fluids returned him to normal by Saturday morning.
Citrus oil and Pennyroyal oil are two other essential oils commonly used for flea prevention and treatment. Citrus oil causes the same types of neurological problems as tea tree oil and is particularly toxic to cats – causing death in several cats that used an “organic” citrus oil dip according to the label directions. Pennyroyal oil can cause severe problems in dogs. It can cause problems with red blood cells and is extremely damaging to the liver.
Wintergreen oil is sometimes used to treat muscle aches and pains because it contains salicylates. Salicylates are similar to active ingredient in aspirin. Cats are very sensitive to salicylates and if they are exposed to wintergreen oil they can develop vomiting, diarrhea, and problems with their liver or bone marrow.
Camphor oil is another oil that is used to treat itchy skin. It can cause vomiting, abdominal pain, tremors, seizures, and it is also toxic to the liver.
For my next post, I’ll cover my favorite essential oil products. And if you ever have questions about the safety of an essential oil (or any other product) ask your veterinarian – we are here to help you and to protect the health of your pet.
The following is a list of toxic and potentially toxic essential oils from Small Animal Toxicology (Peterson and Talcott).
Toxic: Boldo leaf, Wormseed, Mustard, Armoise, Pennyroyal, Tansy, Thuja, Calamus, Wormwood, Bitter almond, Tree wormwood, Buchu, Horseradish, Lanyana, Southernwood, Western red cedar
Potentially Toxic: Wintergreen, Cornmint, Savory, Clover leaf, Basil, Hyssop, Sassafras, Myrrh, Birch, Bay leaf, Oregano, Tarragon, Tea Tree, Savin.
Jenn Pet Vet's Blog 
Thanks for this post. Lot’s of people assume that since essential oils are natural there’s no wrong way to use them. This person may have thought that since undiluted tea tree is okay for human skin that it would be okay for a pet, not realizing that a human adult should limit neat exposure to 1-2 drops max. Pets and children are much smaller of course and therefore need far less oil and that oil should be diluted in a carrier.
Christina, thanks for commenting on my post. I’d love to talk to you sometime about aromatherapy – and take one of your classes (sorry I missed the January classes). Please email me at jennpetvet@mac.com if you’d like to set up a time to chat.