Tea tree oil is Melaleuca oil. It comes from the leaves of the tea tree, Melaleuca alternifolia. This tree is native to south-east Queensland and the north-east coast of New South Wales, Australia. Tea tree oil is for sale extensively on Amazon. It is therefore readily available to many millions of people.
Many websites say it has great benefits. One of those websites is MEDICAL NEWS TODAY. It is described as an antibacterial, an anti-inflammatory drug, an antifungal, an antiviral, it treats acne and athlete’s foot and contact dermatitis. It can be used to treat dandruff and cradle cap, headlice and nail fungus. In a gel can be good for oral health. It’s an amazing natural product. No doubt it is highly popular. There are warnings at the base of that website’s page. The warning should be at the top of the page.
And because it is so popular, I think that it can be dangerous. Whether the product is safe or not depends upon its concentration and how it is administered. It can’t be swallowed as the consequences are numerous in terms of health. And there are potential health consequences when applied topically to humans and pets.
A report about tea tree oil published in 1998 tells us that it was first isolated in 1925 (‘Australian tea tree (Melaleuca alternifolia) oil poisoning in three purebred cats‘). It has many potential benefits. In the 1990s, products containing tree tea oil were sold for use on companion animals including shampoos for cats, dogs, ferrets and horses. One such tea tree oil product was similar to the one used on “these cats”.
“These cats” is a reference in the report mentioned which concerned 3 female Angora cats presented to a veterinarian in a clinic in north central Oklahoma. The cats had been acquired by a breeder who had them vaccinated and treated for fleas. They had a severe flea infestation. They were shaved and it appears that the breeder topically applied a flea treatment labelled as a spot treatment and that it would repel fleas when diluted and used as a dip. That product contained 100% oil of Melaleuca alternifolia i.e. tea tree oil. The oil was applied directly to the cats’ skin and 2 1-ounce (approximately 60 mL) bottles were used on the three cats.
Within five hours of treatment one cat (cat 1) was hypothermic and uncoordinated. They couldn’t stand but were alert. Cats 2 and 3 were admitted later that day. Cat 2 was comatose with severe hypothermia and dehydration. Cat 3 was alert and nervous, slightly ataxic and trembling. “Ataxic” means uncoordinated. All cats had a strong minty odour similar to that of tea tree oil product.
They were bathed in a mild detergent to remove any remaining oil from their skin. They were given activated charcoal to absorb any ingested tea tree oil. They were given dexamethasone. Cats 1 and 2 were given isotonic saline solution intravenously for rehydration and their body temperatures were increased using heat lamps and warm water bottles.
Cat 3 recovered within 24 hours while cat 1 recovered after 48 hours. Cat 2 improved over 3 days but remained uncoordinated. On day 3, cat 2 was found dead that evening. So, two cats recovered and one was killed by a heavy tea tree oil topical treatment.
Tea tree all toxicosis reported in dogs and cats has been associated with misuse of the product. And this is the point of the article. With so much of the product available for human use and such well-publicised benefits, it seems a foregone conclusion that a cat owner somewhere will decide to use it on their cat as it’s a natural product and there may be a presumption that natural products are safer than commercially prepared “chemicals” and “drugs”. This certainly is not true in respect of this product.
Back in 1998 knowledge about the toxicity of Melaleuca oil was variable in respect of health food store personnel and natural healthcare practitioners. At that time many health food store personnel believed that tea tree oil was non-toxic. As many people are going to buy this product without veterinary advice of any kind, it would seem to me that it is potentially, inherently dangerous to cats.
Below are some more articles on products toxic to cats.