Are essential oils dangerous to cats?

Lately I’ve been asked about essential oils and cats by many clients. Is it safe to diffuse essential oils around cats? Will essential oils harm the cat? Which essential oils are toxic? Are any essential oils safe, or even beneficial to cats?

Let’s start with the basics – what ARE essential oils really? They are chemicals that are extracted from aromatic (smelly) plants. They may be found in flowers, seeds, leaves…anywhere in the plant! These are the chemicals that give plants their unique fragrance. The oil compounds are extracted through a chemical process, usually one similar to distilling. Essential oils are classified as “volatile chemicals”, basically meaning they have a low boiling point. This is why diffusing works so well – the property of the oil makes it change from liquid to gas at relatively low temperatures. Essential oils also are lipophilic – the fatty molecule is attracted to the lipid (fatty) cell membrane and passes through readily, entering the cell. This is why essential oils absorb through the skin so well. It’s also why they can irritate the respiratory tract so easily – these molecules go into the lungs and soak right in!

Essential oils don’t necessarily come from exotic plants found in the rainforest. They can come from garlic, basil, parsley… items you have in your pantry. These oils are complex, and can be comprised of hundreds of compounds! (It’s difficult to reproduce these synthetically in a laboratory for this reason.)

So what makes essential oils dangerous to cats? After skin contact (and quick absorption) or ingestion (cat grooms it off the skin or licks the oil) the oil is processed by the liver. Cats’ livers are rather sensitive and inefficient. They don’t even have all of the enzymes most other species of animal have that help deal with foreign chemicals or toxins. (This is also why cats get hepatic lipidosis/fatty liver and dogs don’t.) So instead of processing and excreting the oils, like other species might, the liver cells in cats just die -not cool.

Another factor that makes cats more sensitive to essential oils is their size. With any toxin, smaller animals require less of whatever it is to have adverse effects.

essential oils cat

According to the veterinary specialists at the Pet Poison Helpline, the following essential oils are particularly toxic to cats: oil of wintergreen, oil of sweet birch, citrus oil (dlimonene), pine oils, Ylang Ylang oil, peppermint oil, cinnamon oil, pennyroyal oil, clove oil, eucalyptus oil, and tea tree oil. There may be others not yet included on this list, that we don’t know about… yet. Many of these contain a class of chemical called Phenols. These are particularly poisonous to cats, kinda like chocolate is poisonous to dogs. It’s one of those species-specific things.

Obviously, with their tenacious skin absorption, essential oils should not be applied directly to a cat. But what about diffusing? As in “forget the cat, I am treating myself!” Products with a scent of essential oil, but a low percentage of oil in terms of composition, are generally not considered as dangerous (like scented candles, potpourri, etc). The highest risk is with the newer “active” diffusers -these actually propel tiny oil droplets into the air. Well, what goes up must come down, and if the diffuser is anywhere near your cat or his food/water or bedding, we now have a cat with essential oil droplets ON the skin. Next step is the quick absorption, or the cat can also ingest the oil while grooming. Additionally, the droplets can be inhaled, causing lung irritation.

Cats who end up in the hospital typically have been exposed to essential oils either intentionally (well-meaning owner inadvertently poisons the cat – please don’t be that person!) or accidentally, via active diffusers. How do you know if your cat is affected? Symptoms of pulmonary (lung) reaction would be coughing, acting like there’s a hairball that won’t come up, breathing hard or fast, or panting like a dog. Symptoms of liver or systemic absorption would be lethargy, vomiting, and diarrhea. Signs of systemic toxicity would be tremors, walking like a drunk, or general confusion. If your cat has ANY of these symptoms, stop diffusing and get to the veterinarian. If your cat is having breathing trouble, getting the cat into some fresh air quickly can do wonders!

The current recommendation by veterinary toxicologists is to avoid contact between essential oils and cats – ANY oil – until we know more. Products that smell of essential oil, but have a low concentration (shampoo, lotion, candles, etc) are fine to use with a cat in the house. The main concern is the active diffusers of the highly concentrated oils, and the oil droplets making their way to your cat. Why chance it?

Posted in General health, Myths & Hot Topics, Pet poisons.


  1. Your information is greatly appreciated!
    What about a ‘plant based’ item made up of oils of lemongrass, peppermint & thyme…it is supposed to be ‘earth friendly’ & safe around pets… it was bought because of this & I do not want to use chemical sprays to keep the ants away that have invaded my house! But reading about essential oils concerns me! They are out of reach from the cats & dog, but the odor is quite potent. There is no humidifier or anything used, but want to know if even breathing this in could be harmful!?!?

  2. I have a 6 month old kitty who loves to lick and sniff me. You say at the end that lotions and candles are safe but what if I have a peppermint/tea tree oil lotion and soap that I’m using and she licks me? Will this harm her?

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