FrançaisAre essential oils toxic to cats?
Yes, many are. Essential oils are absorbed quickly through the gut, the skin, the lungs and the lining of the mouth, and the more concentrated the oil, the greater the risk [1]. Cats are more sensitive than dogs [1]. If your cat licked, was sprayed with or had an essential oil or liquid potpourri put on its fur, call your vet or a pet poison line now, even if it seems fine [9].
Oils listed as poisonous to cats include cinnamon, citrus, pennyroyal, peppermint, pine, sweet birch, tea tree (melaleuca), wintergreen and ylang ylang [9]. Eucalyptus is among the oils that can cause seizures [1]. No essential oil has been shown to be safe for cats, so ask your vet before using any oil or herbal product on or around your cat [9]. Essential oils come from plants, and many plants are toxic to cats and dogs too.
Tea tree oil on the skin: the most common case
Tea tree oil, also called melaleuca oil, is the essential oil most often reported in pet poisonings [1, 10]. A few concentrated drops on the skin or swallowed can cause severe poisoning, while pet shampoos containing less than 1 to 2% are generally considered non-toxic when used as labeled [10].
Most cases are well-meant. In a study of 337 dogs and 106 cats exposed to 100% tea tree oil and reported to the ASPCA Animal Poison Control Center from 2002 to 2012, the oil was used on purpose in 89% of the animals [2]. It went on the skin in half of them, on the skin and in the mouth in 30%, and was swallowed in 15% [2]. Signs started within 2 to 12 hours and lasted up to 72 hours; younger and smaller cats were more likely to become seriously ill [2]. Earlier poison-center reports describe oil put on the skin to treat skin problems at inappropriately high doses [4], and tea tree oil poisoning has been reported in three purebred cats [3].
Like the dog flea products that poison cats in permethrin poisoning, the harm here comes from a product put on the coat.
Why cats are so sensitive
The liver clears many drugs and plant compounds by attaching a sugar acid to them, a step called glucuronidation. Cats lack enough of the enzyme that does this (glucuronyl transferase), so they are very sensitive to the phenol and phenolic compounds found in some oils [1]. Lab studies explain why: one of the genes for this enzyme family (UGT1A6) does not work in cats, and cat liver makes several of these compounds much more slowly than dog liver [8, 16]. The authors link this to the cat’s strict meat diet, which rarely exposes it to plant compounds [8].
The same weakness is why cats are so easily poisoned by acetaminophen (Tylenol). Grooming adds to the risk: oil on the coat is licked off and swallowed [1, 9]. Very young cats, kittens and cats with liver disease are more sensitive [9].
Other oils, diffusers and liquid potpourri
Each oil carries its own risks. Some can harm the liver, others can cause seizures [1].
| Product | Main concern | What has been reported |
|---|---|---|
| Tea tree (melaleuca) | Nervous system, liver | Drooling, lethargy, wobbliness, weakness, tremors [2, 4]; low body temperature; liver failure in cats [10] |
| Pennyroyal | Liver | Toxic to the liver [1, 7]. A dog treated for fleas with pennyroyal oil vomited within 2 hours and died within 48 hours [6] |
| Wintergreen, sweet birch | Aspirin-like poisoning, seizures | High in methyl salicylate, a form of aspirin [1] |
| Cinnamon, cassia bark, birch tar | Liver | Listed as potentially toxic to the liver [1] |
| Eucalyptus, cedar, sage, hyssop, wormwood | Seizures | Listed among oils that can cause seizures [1] |
| Citrus (d-limonene) | Nervous system, temperature | In cats: drooling, a marked drop in body temperature, shivering and wobbliness [7] |
| "Natural" flea products with oils | Several signs | 36 of 39 cats had side effects, even when most products were used as labeled; agitation and drooling were common [5] |
| Liquid potpourri | Burns, whole-body effects | Burns of the lips, tongue, gums and throat after a few licks; pawing at the mouth, difficulty breathing [11] |
Diffusers: passive diffusers such as reeds or candles do not release droplets, so the main hazard is irritation of the airways, unless the diffuser is tipped over [1]. Active diffusers, such as ultrasonic or nebulizing models, release microdroplets that settle on the coat; the cat then absorbs them through the skin or swallows them while grooming [1]. Breathing in oils is also a hazard for cats with airway disease such as feline asthma [1].
Liquid potpourri: many contain cationic detergents, which burn the mouth; cats are at higher risk because of grooming, and mouth signs appear within 6 to 12 hours [12]. Cats can be exposed by tasting simmering potpourri or touching liquid from a leaking or overturned pot [9].
Signs and what to do
Signs can start within minutes to hours after any route of exposure [1]. The most common after the oil is swallowed or put on the skin are vomiting, lethargy, drooling, wobbliness and not eating [1]. Look also for [9]:
- A scent of oil on the coat, skin or breath, or in vomit.
- Drooling, pawing at the mouth or face, red or burned lips, gums, tongue or skin.
- Wobbly or uncoordinated walking, weakness, muscle tremors.
- Difficulty breathing; with inhaled oils, watery eyes and nose, coughing or wheezing [1].
- A low body temperature, a slow heart, seizures or paralysis of the hind legs in severe cases [1].
What to do: call your vet or a pet poison line right away, and bring the bottle or packaging [9]. If the product is on the skin or fur, the Pet Poison Helpline advises washing it off quickly with liquid dish soap [9]. Do not make your cat vomit and do not give activated charcoal: with essential oils, vomiting risks the oil going into the lungs [1, 9]. Move your cat to fresh air if it breathed in the oil [1]. Call your vet or a pet poison line whatever the amount.
What the vet checks, and why
The diagnosis mostly rests on what you tell the vet, helped by the smell of oil on the cat or in its vomit [1]. As with any poisoning, the vet runs a complete blood count and a chemistry panel [1]; the aim is to see whether the liver and kidneys are affected [9]. These panels are explained in cat blood work explained.
- Abbreviation ALT, sometimes written ALAT or SGPT, in the liver block of the chemistry panel.
- Result 310 U/L in this illustrative cat line: above the interval. Tea tree oil is one of the essential oils that can harm the liver [1].
- Unit U/L: units of enzyme activity per liter of serum.
- Laboratory interval The example uses the cat interval of the Merck Veterinary Manual [15]; each laboratory sets its own.
- Flag H: above the interval. ALT is a specific marker of liver cell damage in cats; it peaks about 48 hours after an acute injury, and a hemolyzed sample can raise it falsely in cats [14].
| Check | What can be found | Why it matters |
|---|---|---|
| Body temperature | Low | A low temperature is reported with tea tree oil [10] and, in cats, with citrus oil [7] |
| ALT and other liver values | High | Tea tree, pennyroyal and cinnamon oils can harm the liver [1]; ALT signals liver cell damage in cats [14]. See high liver enzymes in cats |
| Kidney values | Sometimes high | Kidney failure is a possible effect [1] |
| Clotting tests and blood sugar | Abnormal if the liver fails | Recommended, and blood sugar repeated, when the liver is not working well [1] |
| White blood cell count | Often high after liquid potpourri | Cats poisoned by cationic detergents often have a fever and a high white cell count [12] |
| Chest X-rays | Lung changes | Done when the oil was breathed in or breathing is abnormal [1] |
Care and outlook
There is no antidote; treatment is supportive care until the signs resolve, such as a bath to remove the oil, fluids, medicines to protect the liver and to control tremors or seizures, and oxygen if needed [1, 9]. In skin exposures to tea tree oil reported to a poison center, supportive care led to recovery without lasting effects within 2 to 3 days [4]. With natural flea products containing oils, half of the animals with a known outcome recovered with bathing alone; 1 cat died and 1 cat and 1 dog were euthanized [5]. With early treatment, most cats survive [9].
Related articles
Another household danger for cats: lily toxicity.
En français : huiles essentielles et chat.
Questions to ask your veterinarian
- Which oil was in the product, and is it one that can harm the liver?
- Are my cat’s ALT and other liver values normal, and when should they be rechecked?
- Are the kidney values normal?
- Is my cat’s temperature normal, and does it need to stay in the hospital?
- Which flea product is labeled for cats and right for mine?
Get your cat’s blood results explained.
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Frequently asked questions
What oils are not safe to diffuse around cats?
No essential oil has been shown to be safe for cats. Oils listed as poisonous to cats include cinnamon, citrus, pennyroyal, peppermint, pine, sweet birch, tea tree, wintergreen and ylang ylang [9]. Active diffusers release droplets that land on the coat and are licked off [1]. The Merck Veterinary Manual advises keeping pets out of the room while a diffuser runs and airing the room afterwards [1]. Ask your vet before using any oil around your cat.
How long does essential oil poisoning take in cats?
Signs can appear within minutes to hours [1]. With 100% tea tree oil, signs started within 2 to 12 hours and lasted up to 72 hours [2]. Do not wait for signs: call your vet or a pet poison line as soon as you know your cat was exposed.
Is lavender safe for cats?
There is no reliable evidence that lavender oil is safe for cats. The lavender plant is listed as toxic to cats by the ASPCA, because of linalool and linalyl acetate, with nausea and vomiting [13]. Ask your vet before using any lavender product near your cat.
What happens if my cat licks tea tree oil?
Call your vet or a pet poison line now. Even a few concentrated drops swallowed can cause severe poisoning, with drooling, stumbling, weakness, tremors and a low body temperature, and liver failure in some cats [10]. Do not make your cat vomit [1]. Call your vet or a pet poison line whatever the amount.
Can you put tea tree oil on a cat for fleas?
No. Concentrated essential oils should never be applied to pets [1], and tea tree oil is the oil most often reported in pet poisonings [1]. Even "natural" flea products with essential oils caused side effects in 36 of 39 cats [5]. Use only a flea product prescribed or labeled for cats, chosen with your vet.
Sources
- Benson K. Toxicoses From Essential Oils in Animals. Merck Veterinary Manual, reviewed 2025. merckvetmanual.com/toxicology/toxicoses-from-household-hazards/toxicoses-from-essential-oils-in-animals
- Khan SA, McLean MK, Slater MR. Concentrated tea tree oil toxicosis in dogs and cats: 443 cases (2002-2012). J Am Vet Med Assoc. 2014;244(1):95-99. doi.org/10.2460/javma.244.1.95
- Bischoff K, Guale F. Australian tea tree (Melaleuca alternifolia) oil poisoning in three purebred cats. J Vet Diagn Invest. 1998;10(2):208-210. doi.org/10.1177/104063879801000223
- Villar D, Knight MJ, Hansen SR, Buck WB. Toxicity of melaleuca oil and related essential oils applied topically on dogs and cats. Vet Hum Toxicol. 1994;36(2):139-142. pubmed.ncbi.nlm.nih.gov/8197716
- Genovese AG, McLean MK, Khan SA. Adverse reactions from essential oil-containing natural flea products exempted from Environmental Protection Agency regulations in dogs and cats. J Vet Emerg Crit Care. 2012;22(4):470-475. doi.org/10.1111/j.1476-4431.2012.00780.x
- Sudekum M, Poppenga RH, Raju N, Braselton WE Jr. Pennyroyal oil toxicosis in a dog. J Am Vet Med Assoc. 1992;200(6):817-818. pubmed.ncbi.nlm.nih.gov/1568929
- Nicholson SS. Toxicity of insecticides and skin care products of botanical origin. Vet Dermatol. 1995;6(3):139-143. doi.org/10.1111/j.1365-3164.1995.tb00057.x
- Court MH, Greenblatt DJ. Molecular genetic basis for deficient acetaminophen glucuronidation by cats: UGT1A6 is a pseudogene, and evidence for reduced diversity of expressed hepatic UGT1A isoforms. Pharmacogenetics. 2000;10(4):355-369. doi.org/10.1097/00008571-200006000-00009
- Schmid R, Brutlag A, Flint C. Essential oil and liquid potpourri poisoning in cats. Pet Poison Helpline for VCA Animal Hospitals, 2026. vcahospitals.com/know-your-pet/essential-oil-and-liquid-potpourri-poisoning-in-cats
- Pet Poison Helpline. Tea tree oil. petpoisonhelpline.com/poison/tea-tree-oil
- Pet Poison Helpline. Liquid potpourri. petpoisonhelpline.com/poison/potpourri
- Gwaltney-Brant SM. Toxicoses From Corrosive Agents in Animals (cationic detergents). Merck Veterinary Manual, reviewed 2025. merckvetmanual.com/toxicology/toxicoses-from-household-hazards/toxicoses-from-corrosive-agents-in-animals
- ASPCA Animal Poison Control. Toxic and non-toxic plants: Lavender. aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/lavender
- eClinPath (Cornell University). Alanine aminotransferase. eclinpath.com/chemistry/liver/liver-injury/alanine-aminotransferase
- Merck Veterinary Manual. Serum biochemical analysis reference ranges. merckvetmanual.com/reference-values-and-conversion-tables/reference-guides/serum-biochemical-analysis-reference-ranges
- van Beusekom CD, Fink-Gremmels J, Schrickx JA. Comparing the glucuronidation capacity of the feline liver with substrate-specific glucuronidation in dogs. J Vet Pharmacol Ther. 2014;37(1):18-24. doi.org/10.1111/jvp.12067
Laboratory methods and reference intervals vary. This article explains; it does not diagnose. For a decision about your pet, use the original report and talk to your veterinarian. Our editorial policy.