Is Tea Tree Oil Dangerous to Cats and Dogs?

Touted for its many benefits to human health, tea tree oil has become extraordinarily popular in recent decades, as have many complementary and alternative medicines. Boasting anti-fungal, antibacterial, antiviral, antipruritic, anti-inflammatory, and antiparasitic effects, tea tree oil is one of the most versatile and potent of the essential oils. It's commonly found in medicine cabinets in millions of homes — often in a 100% proof formulation.

Golden retriever and British short hair cat lying together on floor
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However, while tea tree oil's beneficial effects have made it a popular "natural" remedy for people around the world, it is known to be toxic to pets in large amounts — in fact, in concentrations higher than 1.0% topical, it's dangerous. Therefore, tea tree oil should be used with caution in dog or cat applications, and always appropriately diluted to be safe for your pet. And keep in mind that tea tree oil is toxic to both pets and humans when taken orally.

History of tea tree oil

Essential oils are volatile, organic constituents of plants. Tea tree oil, extracted from the leaves of the melaleuca alternifolia tree native to Australia, is one of the most potent of essential oils. It's available worldwide as a neat oil and is an active component in an array of products such as soaps, toothpaste, lotions, and skin creams.

Tea tree oil is clear to pale yellow with a camphor-like smell and has bactericidal and fungicidal properties. It's best known for its antiseptic and anti-inflammatory actions. It's also a component — in small concentrations of 0.1 to 1% —in skin creams developed by veterinarians for dogs and cats.

The leaves of the tea tree, which is also known as the "narrow-leaved paperbark" or "snow-in-summer," have been used by the indigenous peoples of Australia as an herbal medicine for thousands of years. Although toxic if ingested, tea tree oil can be safely used on the surface of the skin to treat myriad skin disorders ranging from acne and sunburn to warts and athlete's foot.

Years ago, if someone were to try and leave Australia with a cutting of the tea tree for propagation elsewhere, they'd be jailed. But eventually, tea trees, members of the myrtle tree family, were introduced to America, and it's now widely grown in the southern states, particularly Florida.

essential oil dripping on the green leaf from pipette
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How dangerous to pets is tea tree oil?

Unfortunately, due to its popularity and a proliferation of misinformation about tea tree oil online, the Pet Poison Helpline receives several calls every year for the misuse of tea tree oil in pets that result in toxicosis, which is often fatal. For example, 7 drops of 100% tea tree oil has resulted in severe poisoning, and applications of 10-20 milligrams of 100% oil have resulted in poisoning and death in both dogs and cats. Bottom line: tea tree oil can be extremely dangerous to dogs and cats when used inappropriately.

Tea tree oil toxicity in dogs and cats

"Natural" products like tea tree oil should not be confused with non-toxic or non-poisonous products; if used in the wrong way, natural substances can, indeed, be poisonous.

In fact, the same group of natural chemicals that make tea tree oil so effective against bacteria and fungi make it equally, if not more, toxic. Called terpenes, these toxic agents are rapidly absorbed into the body, whether the oil is applied to the skin or accidentally ingested.

Consequently, tea tree oil is one of the top ten most common causes of toxin seizures in cats, according to the American Society for the Prevention of Cruelty to Animals Animal Poison Control Center. And a report by the Journal of American Veterinary Medical Association based on 10 years of data from the ASPCA Animal Poison Control Center found that tea tree oil in amounts ranging from 0.1 to 85 ml. was intentionally used in 395 of 443 dog and cat poisoning cases in the United States and Canada during that period, with the rest being accidental exposure. Overall, the exposure was through the skin after a topical application (cutaneous) in 50% of cases, cutaneous and oral in 30%, and oral in 15% of the pets.

Clinical signs of toxicosis developed in the pets within two to 12 hours and lasted up to 72 hours with the most common signs being increased salivation or drooling, depression, muscular weakness or partial paralysis caused by nerve damage (paresis), lack of coordination caused by brain damage (ataxia), and tremors. Age and weight were a significant factor with major illness occurring in younger and smaller cats.

essential oil bottle and dropper with plant leaf in background
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Why is tea tree oil so easily misused?

In Australia, where tea tree oil originated, the oil is listed as a schedule 6 toxin and must be labelled accordingly. Packaging requires child-proof containers and cautionary labeling. However, in the US and Canada, such packaging and labeling are not required.

A 10 year-long veterinary study of tea tree oil toxicity in pets found that 89% of US owners who used 100% tea tree oil assumed that it was safe. The researchers believed the lack of cautionary labeling and packaging was a major reason that tea tree oil was presumed to be safe by the pet owners.

Call the Pet Poison Helpline

Pet Poison Helpline is an animal poison control service available 24 hours, 7 days a week for pet owners and veterinary professionals who require assistance treating a potentially poisoned pet. If your dog or cat was exposed through accidental ingestion or improper dilution to tea tree oil in higher than .01-1.0% strength in a topical application (not oral) concentration, call your veterinarian or the Pet Poison Helpline at (855) 764-7661 immediately for treatment advice — exposure to tea tree oil is potentially life-threatening to your pet, therefore, you must act quickly. VCA Hospitals warn that fast and aggressive treatment is essential to prevent any toxic effects from developing.

Symptoms of tea tree oil poisoning

If your dog or cat has been exposed to tea tree oil in large amounts and exhibits any of the following clinical signs of poisoning, seek veterinary treatment immediately:

  • Depression
  • Vomiting
  • Collapse
  • Low body temperature
  • Weakness
  • Staggering or walking "drunk"
  • Immobility such as inability to walk
  • Tremors
Essential Oils on a Market Stall
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Coma, increased liver enzymes, and death can occur if not treated in time. Treatment is based on the symptoms and their severity.

Treatment and prognosis for tea tree oil poisoning in dogs

With no antidote available for terpenes, the primary component in tea tree oil, your veterinarian will perform blood work to determine if your dog's liver and kidneys have been affected. Intravenous (IV) fluids may be used for hydration. If the mouth or esophagus has been burned by the oil, a soft diet or feeding tube may be necessary. Other treatments may include pain medication, antibiotics, medication to protect the liver, anti-vomiting medication, and medications to protect the stomach, says VCA Hospitals.

Tea tree oil is one of the most toxic of the essential oils and recovery will depend on the severity of the incident and how much of the oil was used. However, with early intervention and supportive treatment, most dogs can survive.

Tea tree oil poisoning in cats

The impact of tea tree oil poisoning in cats is more severe than in dogs since cats have more of an adverse reaction to essential oils in general. "Cats lack an essential enzyme in their liver and have difficulty metabolizing and eliminating certain toxins like essential oils," explains Kia Benson, DVM at Pet Poison Helpline. As in dogs, the higher the concentration of the essential oil, the greater the risk to the cat.

In addition to tea tree oil, be aware that other essential oils are also highly toxic to cats, including oil of wintergreen, oil of sweet birch, citrus oil (dlimonene), pine oils, Ylang Ylang oil, peppermint oil, cinnamon oil, pennyroyal oil, clove oil, and eucalyptus oil.

Prevention of tea tree oil poisoning in dogs and cats

Keep tea tree oil and other essential oils out of reach of your pets and always consult with your vet before using tea tree oil on your dog or cat to ensure the correct dilution and application procedure.

Conclusion

Camphoraceous tea tree oil is toxic to pets in large amounts; anything more than a 1.0% concentration can be dangerous. And tea tree oil is toxic to both pets and humans if taken orally. Remember, just because a product is natural does not mean it's non-toxic or non-poisonous when used incorrectly.

If your dog or cat has been exposed to tea tree oil and exhibits symptoms; including weakness, tremors, and staggering as if drunk, call the Pet Poison Helpline at (855) 764-7661 and take your pet to your vet or an emergency veterinary hospital immediately.

Correct handling, storage, and the proper dilution of tea tree oil for topical use in pets is vital for their safety.