The liver is most often the organ which is affected by essential oils. Cats' livers are simply not the same as humans' livers, and they lack the ability to properly metabolize the various compounds in essential oils. A more complete and technical description of this insufficiency can be found in this article by Dr. Khan.
Toxicity in cats can occur very quickly, through internal or external application, or over a longer period of time, through repeated or continuous inhalation of essential oils, but either way, it can lead to serious liver damage or even death.
Essential Oils Potentially Toxic to Cats
(This list is not all-inclusive)
- Lemon Oil
- Lavender Oil
- Melaleuca Oil
- Tea Tree Oil
- Cinnamon Bark Oil
- Wintergreen Oil
- Thyme Oil
- Birch Oil
- Other oils containing phenol
A Word About Hydrosols
Hydrosols, which are described as the essence left in plants after the oil has been distilled out, have been the topic of a bit of controversy. Some articles advocate the use of hydrosols as a safe alternative to essential oils, while one authority recommends caution in their use.
This article contains just a short overview of some of the dangers to cats by the use of essential oils. The Lavender Cat web site offers extensive background information on this subject. I highly recommend it for anyone who wants to use aromatherapy for personal benefits, while securing the safety of their cats.