Melaleuca or Tea Tree oil, although used in many pet products, is an apparent risk to cats and even humans! Cats do have a different metabolism then other mammals and could suffer liver damage from inproper essential oil use! In KittenSafe, we We DO NOT use Tea Tree Oils or a few others with similar risks! Further, we use only pure refined oils and at concentrations below the recommended dilutions suggested by leading Aromatherapists for direct skin application.

If you attempt to make your own concoctions, please read the following plus the public data at the EPA and FDA web sites on essential oils allowed in foods, pesticides, etc. and of course the many Aromatherpy books suggestions for pets, before assuming any oil is safe to use at even 1% strength!

The following are mostly opinion and not scientifically generated data but lends a good base from which to work, although a few conflict with eachother. All chemical compounds do have a risk, life itself is risky, but responsible use can reduce risks to very acceptable levels. Few realize chocolate or even onions can be fatal to cats, or that there are thousand of cat products on the market containing unsafe oils, only because they became "popular additives", such as Tea Tree Oil did!

From many sources on the web we present the following snippets of data: (You should keep in mind that most sources class Tea Tree oil as one of the safest of the essential oils and claim it may be applied neat or undiluted, but the following seems to indicate otherwise!!

"Toxicity: The most common clinical signs reported to the Animal Poison Control Center by veterinarians with adverse reactions in dogs and cats after dermal exposure of melaleuca oil include ataxia, incoordination, weakness, tremors, behavioral disorders and depression. The acute toxcicity (rabbit dermal LD 50 and rat oral LC 50) for the major terpenic compounds (linalool, ocimene, alpha-terpinene, 1,8-cineole, terpinolene, camphene) ranges between 2 and 5 g/kg body weight, which is considered a moderately toxic range. From a toxicologic standpoint melaleuca oil can be compared to oil of turpentine, which is readily absorbed from the gastrointestinal tract and skin.

Jacobs MR, Hornfeldt. Melaleuca oil poisoning. Clinical Toxicology 
1994;32:461-464. 

Abstract: "A 23-month-old boy became confused and was unable to walk thirty minutes after ingesting 
less than 10 mL (two teaspoons) of T36-C7, a commercial product that contained 100% melaleuca oil. The 
child was referred to a nearby hospital. His condition improved and he was asymptomatic within 5 hours 
of ingestion. He was discharged home the next day. Melaleuca oil, extracted from the Melaleuca alternifolia, 
contains 50-60% terpenes and related alcohols. This case report suggests that ingestion of a modest 
amount of a concentrated form of this oil may produce signs of toxicity." 
---------------------------------------------------------------------- 
Del Beccaro MA. Melaleuca oil poisoning in a 17-month-old. Vet 
Human Toxicol 1995;37:557-8. 
Abstract: "Ingestion of significant quantities of melaleuca oil or Australian tea tree oil has been described 
only once in medical literature. This report describes a 17-month-old male who ingested less than 10 mL 
of the oil and developed ataxia and drowsiness. Emergency physicians, poison control personnel and 
pediatricians should be aware of potential toxicity from this product." 
---------------------------------------------------------------------- 
Elliott C. Tea tree oil poisoning. Med J Australia 1993;159:830-831. 
A 60-year-old male ingested 0.5 teaspoonful of tea tree oil and developed a dramatic rash, malaise and 
neutrophil leucocytosis. 
---------------------------------------------------------------------- 
Seawright A. Tea tree oil: comment. Med J Australia 1993;159:831. 
This author commented that some tea tree oils contain a high concentration of 1,8-cineol (eucalyptol, 
cajeputol). Toxicity similar to that of eucalyptus oil would be expected. Toxic does of eucalyptus oil 
range from 5-30 mL in humans, with symptoms including respiratory depression, coma and death. 
deGroot AC, Weyland JW. Systemic contact dermatitis from tea tree oil. Contact Dermatitis 1992;27:279-280. 
This report in a human showed that this reaction was caused by the allergin, cineol present in the tea tree oil. 
---------------------------------------------------------------------- 
CONCLUSION: One should be aware that that tea tree oil (melaleuca oil) is potentially toxic to animals and 
avians when applied topically. Use this information and your own judgment when deciding if you feel 
comfortable in applying tea tree (melaleuca) oil to your pets. Tea tree oil should NOT be applied to avians. 
Gillian Willis Avian Veterinarian 
Vancouver, B.C. 

Toxic Components of Tea Tree Oil
Tea Tree oil (melaleuca, Melaleuca alternifolia) is a phenol-containing essential oil. Its active 
ingredients are cyclic terpenes which have a similar structure and action to turpentine 
(a known toxin) - in fact Tea Trea oil makes a good paint solvent! Cats are uniquely sensitive 
to phenolics and other benzene-based compounds. Benzyl alcohol (a preservative) is toxic 
to cats.

The acute toxicity for the major terpenic compounds (linalool, ocimene, alpha-terpinene, 1,
8-cineole, terpinolene, camphene) is 2 - 5 g/kg body weight, which is considered a moderately 
toxic range. From a toxicologic point of view Tea Tree oil is comparable to oil of turpentine, 
which is readily absorbed from the gastrointestinal tract and skin. In addition, cats have relatively 
thin, delicate skin and Tea Tree oil is highly lipophilic (attracted to fats, solvent). This means that 
the oil is absorbed rapidly and enters the bloodstream. These factors may account for the 
poisoning cases reported to the NAPCC.

Mean Percentage Composition of Major Components of Tea Tree Oil, Terpinen-4-ol Type
(the low cineole oil specified by the Standards Association of Australia)
*97 components have been identified, this table relates to major components only.
Component*	Mean  Percentage	Component*	Mean  Percentage	
a-pinene	2.46	g-terpinene	20.20	
a-thujene	0.83	r-cymene	2.80	
beta-pinene 	0.66	terpinolene	3.45	
sabinene	0.45	aromadendrene	1.68	
myrcene	0.86	terpinen-4-ol	37.93	
a-phellandrene	0.44	virdiflorene	1.68	
a-terpinene	9.56	a-terpineol	3.01	
limonene	1.01	d-cadinene	1.49	
beta-phellandrene	0.94	globulol	0.86	
1,8-cineole	3.87	virdiflorol	0.33	

Cats are notoriously sensitive to toxins; their livers are not able to metabolize many substances which may safely be used on dogs (cats have been poisoned through use of dog flea preparations). For this reason, a substance shown to be beneficial and safe for humans may be unsuitable for use on cats. e.g. to cover the area where oil is applied. Cats cannot efficiently metabolize substances present in certain essential oils (including Tea Tree oil), which will therefore build up in the cat's body. This means that they are not efficiently excreted by the body and can accumulate in soft tissues and vital organs. Over a period of time, the substances can reach toxic levels which cause death or symptoms of poisoning.

An owner could therefore use Tea Tree oil in supposedly safe low concentrations for some time with no symptoms, though the cat is being slowly poisoned as the toxins accumulate. This is similar to they way that heavy metals (e.g. lead, zinc) or poly-chlorinated bi-phenols (PCBs) accumulate in the soft tissues and organs. An added danger is that cheap essential oils may be adulterated with other things for various reasons; the combination of substances could be more toxic than the unadulterated oil. The other effects of long term use of Tea Tree oil on cats are not known, especially any carcinogenic (cancer-forming) effects. Nor is it confirmed whether it reacts with prescription medications or non-prescription items such as flea-treatments (sprays, powders and especially long-acting treatments added to the food or applied in absorbable form to the back of the neck). It is therefore recommended that Tea Tree oil is not used within days, possibly weeks, of other treatments.

Other Essential Oils
For the sake of completeness, Tea Tree oil is not the only commonly found essential oil. Herbal remedies contain a variety of oils, a number of which are dangerous to cats. Problems commonly occur when an oil safe for use on humans or dogs are used on cats. Incorrect usage of an oil is almost guaranteed to cause problems. Problems also occur when an oil is 'in fashion' an marketed using anecdotal evidence; its effects on cats may not have been researched properly. Tea Tree oil is currently a fashionable remedy.

There have been cases of poisoning resulting from a single drop of an essential oil (not only Tea Tree oil, though this is the one most readily available to most cat owners) on their paws or belly, or diffusing them in the area where the litter box was located. Often the reaction was considered a "mystery poisoning" and the toxic agent was not readily identified. Many cat products now contain Tea Tree oil: shampoos, coat sprays, 'antiseptic' wipes, ear cleaners, rechargeable flea collars and herbal dips. Some are simply labelled as "herbal oils".

Essential oils which contain phenols are particularly toxic to cats and cause liver damage. These include Oregano, Thyme, Eucalyptus, Clove, Cinnamon, Bay Leaf, Parsley and Savory

Essential oils which contain ketones cause neurological symptoms. These include: Cedar Leaf*, Sage*, Hyssop*, Cyprus*, Lavender, Eucalyptus, Mint ,Caraway*, Citronella ,Clove*, Ginger*, Chamomile, Thyme and Rosemary (those marked * give particular cause for concern).

References: 
Knight, M.J. & Villar, David. Toxicity of melaleuca oil and related essential oils 
applied topically on dogs and cats. Vet Human Toxicol 36(2): April 1994, p139-142.
Florida Veterinary Scene Newsletter, 4(5), May/June 1995.
Promotional leaflet from Pet & Garden Manufacturing plc (Scotland), 1995

Further discussions of Tea Tree Oil toxicity are located at 
http://www.holisticat.com/aromatherapy.html 
& http://www.holisticat.com/essoils_arch.html

The cat has several metabolic idiosyncrasies which make medicating this species a 
slightly riskier proposition: 

1. Delayed biotransformation of many exogenous substances due to decreased UDP-glucuronyl 
transferase activity. Glucuronic acid conjugation is probably the most important process 
for activating and increasing water solubility of xenobiotics. The cat, therefore, does not 
process compounds such as coumarin, morphine, certain sulfonamides and salicylic acid. 

2. Feline hemoglobin has an enhanced susceptibility to oxidation, producing methemoglobinemia 
and Heinz body anemia. Cats are susceptible to fatal anemias produced by acetominophen and by 
onions. 

3. Cat receptors react to certain drugs in anomalous ways; or instance, morphine causes 
excitation, as opposed to sedation, in cats 

4. Feline liver transaminase and deaminase activities are higher than in most species. 

5. Cats are uniquely sensitive to phenolic compounds, and other compounds containing benzene 
rings. Compounds preserved with benzyl alcohol are toxic to cats. Caution should be taken 
with essential oils containing phenols, such as, potentially, thyme, cinnamon, tea tree and 
many others 

The examples given above are by no means all-encompassing -- they were simply all I could 
think of when I wrote the article. I think they give us reason to be concerned about ANY 
herb, nutraceutical, EO, etc that we give a cat for the first time. 
Susan G. Wynn, DVM 

Summary Comment - Reported cases of cat poisioning with undiluted Tea Tree oil seem to always report the strong smell of Tea Tree Oil even days later! This is a great clue that the oils were not metabolized but retained in the tissue, as essential oils exposed to the air will vsporize totally in less then an hour! I.E. you would know if there were a problem within an hour, if the oils aroma lingered on, and thus to look out for the above symptoms!

To research this subject further, we suggest you use Google.com, the best technical search engine, and search for long strings of keywords, such as: cat essential oil poison liver skin. Please remember that most of what turns up is often raw opinion or old wives tales, so sort them out to try and find those worth reading, with scientifically backed data or links to the real facts!

Further info on oil and along with tea
The Fastest SFTP on the planet Go FTP FREE Client