I've been told that tea tree oil is toxic to pets. Can I safely use these products?
Cats are very sensitive to essential oils so please do not use them on your pets, especially directly on them. Their livers can't process the volatile and aromatic compounds the way most animals can because they lack the appropriate enzymes. So as they try to metabolize the compounds in the essential oil, they aren't broken down and eliminated, and can quickly build up to toxic levels.
Cats can absorb these compounds in essential oils by mouth, contact with the skin or by inhalation if they are being used in a diffuser.
Cats are most susceptible to essential oils that contain terpenes (like tea tree oil) and phenols (thyme, oregano, clove). Treat all essential oils as potentially harmful and consult your veterinarian on what you can safely use on your cat.
Sources: http://cats.about.com/od/housekeeping/a/aromatherapy.htm http://www.thelavendercat.com/images/PDF-TheLavenderCat_temp_use.pdf Holistic Aromatherapy for Animals: A Comprehensive Guide to the Use of Essential Oils & Hydrosols with Animals by Kristen Leigh Bell
Its popularity has resulted in some veterinary skin care products that contain small amounts of tea tree oil. In small concentrations (.1% to 1%), tea tree oil is tolerated and safe for cats and dogs.
Unfortunately, the oil's popularity has resulted in larger numbers of households with bottles of 100 percent tree tea oil, and accidental ingestion or improper dilutions of this highly concentrated oil can be harmful to pets.
in other words, as with any pet supply, the reputable brands are probably safe enough and will likely have this info on their label; if you buy some backyard potion beware.