Are Essential Oils Safe Around Cats?

Are essential oils safe for cats? The Merck Veterinary Manual advises that concentrated essential oils should not be applied directly to pets, and notes that cats are more sensitive than dogs because they are deficient in a liver enzyme called glucuronyl transferase.

The ASPCA adds that concentrated (100%) oils can be a danger to pets, and advises keeping bottles up and out of reach.

Diffusing is a grayer area. The ASPCA says a diffuser used for a short time, in a secured area your cat can't get into, is not likely to be an issue.

Here's which oils the sources single out, how diffusers differ, and what to do if your cat gets some on her.

Are essential oils safe for cats? Why cats are more sensitive

The Merck Veterinary Manual describes essential oils as the compounds that give plants their scent. Merck explains that they're absorbed readily through the gut, skin, lungs and the lining of the mouth and nose. The higher the concentration, the greater the risk.

Cats have a particular weak spot. Merck notes that they're deficient in glucuronyl transferase, a liver enzyme, which makes them very sensitive to phenol and phenolic compounds, which some oils contain.

Here's the part that surprises most people. A study in Pharmacogenetics found that one of the genes behind this enzyme, UGT1A6, is a pseudogene (a gene that no longer works) in domestic cats. The same damaging mutations turned up in five other unrelated cats.

Four of the five were also found in a margay, a small wild cat. The authors suggest this most likely reflects the highly carnivorous diet of the cat family, with minimal exposure to defensive compounds that plants make.

Grooming adds to the risk. Merck points out that a cat's natural grooming places her at extra risk from both skin and oral exposure, because oil on the coat can be licked off.

Her nose is part of it too. The ASPCA reminds owners that pets have a much better sense of smell than we do, so a scent that seems light to us may be overwhelming to them.

Which essential oils are most dangerous for cats?

Tea tree oil

Merck says tea tree oil, also called melaleuca oil, has been the most commonly reported essential oil poisoning in pets. The ASPCA warns that concentrated tea tree oil may cause problems with only seven or eight drops.

The clearest data comes from a study in the Journal of the American Veterinary Medical Association. It reviewed 443 dogs and cats, 106 of them cats, poisoned by 100% tea tree oil in ten years of ASPCA Animal Poison Control Center records.

In 89% of cases the oil was used on purpose, most often on the skin. Signs appeared within 2 to 12 hours and lasted up to three days. The most common were drooling, lethargy, weakness or partial paralysis of the legs, wobbly walking and tremors.

Younger and lighter cats were more likely to become seriously ill.

Other oils Merck singles out

Merck lists these oils as potentially harmful to the liver:

• tea tree (melaleuca)
• pennyroyal
• cinnamon oil and cassia bark
• birch tar

And these as oils that can cause seizures: birch, cedar, eucalyptus, hyssop, pennyroyal, sage, wintergreen and wormwood.

Merck adds that wintergreen and birch oils contain high levels of methyl salicylate, a form of aspirin, so they can produce aspirin poisoning.

What about lavender?

The ASPCA lists the lavender plant as toxic to cats. It names linalool and linalyl acetate as the toxic compounds, with nausea, vomiting and poor appetite as the signs. The ASPCA entry covers the plant, and lavender oil is distilled from it.

"Natural" flea products

Merck notes that essential oils turn up in "natural" flea and tick repellents. A study in the Journal of Veterinary Emergency and Critical Care reviewed 39 cats exposed to plant-based flea products exempt from EPA registration.

Ninety-two percent of the cats had at least one adverse effect, and 77% of all the animals had been treated as the label directed. Agitation and drooling were common signs in cats.

What signs should I watch for?

Merck says signs depend on the oil, its strength and how the cat was exposed, and can develop within minutes to hours. After swallowing or skin contact, the most common are vomiting, lethargy, drooling, wobbly walking (ataxia) and not eating.

Merck lists other possible signs as tremors, low blood pressure, stomach ulcers, a slow heart rate, low body temperature, seizures, paralysis of the back legs, skin irritation, liver failure and kidney failure.

The ASPCA's list for oil on the coat includes unsteadiness on the feet, depression, and low body temperature in severe cases. If concentrated oil was swallowed, it adds vomiting, diarrhea and depression.

Are essential oil diffusers safe for cats?

Merck says the type of diffuser changes how a pet is exposed:

• Passive diffusers, such as reed diffusers and candles, don't release droplets of oil. Unless one is tipped over, Merck says the main hazard is irritation of the airways.
• Active diffusers, such as ultrasonic and nebulizing models, release tiny droplets into the air. If the cat is in the same room, Merck notes they can collect on fur, then be absorbed through the skin or licked off.

Merck lists the signs from breathing in oils as watery eyes, a runny nose, nausea, drooling, vomiting, coughing, wheezing, and fast or labored breathing.

Merck says inhaled oils are also hazardous with existing breathing problems, naming feline asthma, airborne allergies, chronic bronchitis and long-term exposure to secondhand smoke. The ASPCA suggests a pet with a history of breathing problems may be best kept away from diffusers altogether.

A note on the evidence: the two case series Merck cites involved oil on the skin or swallowed. We did not find comparable published data on everyday diffusing, so the guidance below is precaution from veterinary toxicologists rather than measured risk.

Merck's guidance for pet owners, with the ASPCA's additions:

• Keep your cat out of the room while the diffuser runs, and ventilate the room afterward (Merck).
• Use diluted rather than concentrated oils, and avoid the oils known to be toxic (Merck).
• Keep the diffuser where your pet can't knock it over, and keep bottles out of reach (ASPCA).

The ASPCA wouldn't recommend using any essential oils where pets have access, unless they're supervised or your vet approved the oil. For more on a closed-up winter home, see our guide on how to keep an indoor cat warm in winter.

What about potpourri, candles and holiday scents?

The ASPCA explains that liquid potpourri and some diffuser liquids may contain cationic detergents, although most mainly contain fragrances, alcohol or essential oils. These detergents can cause significant chemical burns to the mouth, esophagus and other tissues.

The ASPCA adds that cats appear especially sensitive and may develop severe signs even after relatively small exposures. Signs can include drooling, vomiting, mouth irritation or ulcers, trouble swallowing, weakness, uncoordinated walking and breathing difficulty.

Severe exposures may also change blood pressure, body temperature or nervous system function, and aspiration pneumonia is a concern if vomiting occurs. The ASPCA advises storing diffuser liquids and potpourri in secure cabinets and cleaning spills promptly.

Candles count as passive diffusers in Merck's terms. Our guide on how to cat proof a Christmas tree covers the rest of the holiday decorations.

Seasonal flowers carry their own risks. Read our answer to are lilies toxic to cats before any bouquet comes through the door.

One more surprising fact from Merck: essential oils can become contaminated with bacteria. Cases of melioidosis, a serious bacterial infection, occurred in people in the US in 2021 after breathing in contaminated essential oils.

What should I do if my cat is exposed?

The ASPCA advises contacting your veterinarian or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately if you think your pet was exposed. A consultation fee may apply. Merck notes signs can start within minutes to hours.

• Don't try to make her vomit. Merck warns against it because of the risk of the oil being breathed into the lungs (aspiration).
• Ask your vet whether to move her to fresh air or bathe her. Merck lists bathing and fresh air as ways vets remove the oil.
• Keep the bottle or label. Merck notes that diagnosis is generally based on the owner's report of what was used.

In the flea product study, half of the 28 animals with a known outcome recovered with bathing alone. Others needed IV fluids, muscle relaxants or anti-seizure medicine, and one cat died while two animals were euthanized.

Call your vet promptly if your cat:

• has essential oil on her skin or fur, or licked it from a bottle, diffuser or spill
• is drooling, vomiting or not eating
• is wobbly, weak in the back legs or trembling
• seems unusually sleepy or depressed
• is coughing, wheezing or breathing fast or with effort

Questions new cat parents ask

Can I diffuse essential oils around my cat?

The ASPCA says a diffuser used briefly in a secured area your cat can't access is not likely to be an issue. Merck advises keeping pets out of the room and ventilating afterward. The ASPCA suggests avoiding them if breathing is a problem.

Is tea tree oil safe for cats?

Merck says tea tree oil has been the most commonly reported essential oil poisoning in pets, and the ASPCA warns that seven or eight drops of the concentrated oil may cause problems.

Is lavender oil safe for cats?

The ASPCA lists the lavender plant as toxic to cats, with nausea, vomiting and poor appetite as signs. Ask your vet before using lavender oil anywhere your cat can reach it.

Are essential oil flea treatments safe for cats?

In one study, 92% of cats exposed to plant-based flea products had adverse effects, and most animals had been treated as the label directed. Ask your vet for a flea product made for cats.

Can I put diluted essential oil on my cat?

The ASPCA advises that it is best to completely avoid applying essential oils directly to your pet, because of variation in concentration, formulation and quality. Merck gives no safe dilution for cats. Talk to your vet before putting any oil on her.

Sources

• Merck Veterinary Manual: Toxicoses From Essential Oils in Animals
• ASPCA: Is the Latest Home Trend Harmful to Your Pets? What You Need to Know
• ASPCA: Pet Poisons: Be Mindful of These Household Products and Cleaning Agents
• ASPCA: What Pet Parents Need to Know About Corrosive Household Products
• ASPCA Animal Poison Control: Lavender
• Khan SA, McLean MK, Slater MR. Concentrated tea tree oil toxicosis in dogs and cats: 443 cases (2002–2012). Journal of the American Veterinary Medical Association, 2014
• 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. Journal of Veterinary Emergency and Critical Care, 2012
• Court MH, Greenblatt DJ. Molecular genetic basis for deficient acetaminophen glucuronidation by cats: UGT1A6 is a pseudogene. Pharmacogenetics, 2000

This article is for general information and is not veterinary advice. Talk to your vet about your own cat — they know the animal in front of them.

Choolip products are food supplements, not medicine. They are not intended to diagnose or manage any medical condition. If your cat has been diagnosed with a condition, their diet should be set by your vet.