Cats have a unique genetic make-up that gives pause to the use of aromatherapy around them. Because of this, we researched the toxicity of essential oils to cats.
What we found was a lot of contradictory information, with some sources claiming that all essential oils are toxic to cats.
Yet some sources suggest that if you take the proper precautions, all essential oils are safe for use around cats — and that some may even have health benefits for felines.
The truth lies somewhere in between these two extremes. That’s why, if you’re a cat owner who enjoys essential oils, it’s important to do your research before breaking out the diffuser.
Let’s take a closer look at the effects of essential oils on cats and find out how to use them safely around your furry friends.
Your Cat and Essential Oils – Sensitivity in the Nose
Compared to humans, cats have a heightened sensitivity to scents and smells. A 2017 research article in Applied Animal Behavior Science revealed that a cat’s sense of smell is approximately 14 times stronger than a human’s.
200 million scent cells are found in a cat’s nose — a huge difference from the 5 million scent cells in a human‘s nose.
In other words, if you can smell something, your cat can really smell it!
It’s not just the nose, either: cats have scent glands located on the forehead, chin, lips, tail and front paws. They also have the Jacobson’s organ (an additional organ that processes smells) in the upper part of the mouth.
But the true secret behind a cat’s incredible sense of smell can only be revealed on a microscopic level.
Research reveals that all mammals possess three specific proteins located in the nose that function as scent receptors. One such protein, identified as V1R, enables a mammal to distinguish separate scents in a compound.
Humans possess two variations of the V1R protein, while dogs possess nine variations. But cats possess a whopping 30 variations — that means they’re 15 times better than us at breaking down a smell into individual components.
What this reveals is that a cat’s sense of smell is far superior to that of most other mammals. That’s great for feral cats who roam, track and hunt, but it’s a potential source of trouble for housecats who are exposed to essential oils.
Your Cat and Essential Oils – Sensitivity in the Liver
There is a lot of contradictory information concerning the use of essential oils around cats. And in many cases, medical knowledge and practical experience seem at odds with each other.
First, let’s take a look at the medical side of things — specifically, the liver.
In all mammals, the liver is designed to remove the build-up of toxins from the body. Various enzymes in the liver break down and remove different varieties of toxins.
And that means that if an animal is lacking a certain enzyme, it won’t be able to remove the associated toxins.
Unfortunately, cats lack many of these enzymes, including one called glucuronyltransferase. This enzyme is responsible for ridding the body of excess carbolic acid, a type of phenol.
Phenols are a byproduct of plant metabolism and are found in many essential oils. But because cats lack the appropriate enzyme to remove them, phenols can build up in the body, resulting in liver toxicity.
Other compounds found in essential oils can also be toxic. In particular, ketones and terpenes are potential sources of danger when using essential oils around cats.
But at the same time, some research suggests that these same compounds could have health benefits for many cats.
Safe use of essential oils around cats requires solid knowledge about these compounds and familiarity with their presence in various oils. Let’s take a closer look.
12 Signs of Cat Toxicity to Essential Oils
- Arrhythmia / Abnormal Heart Rhythm
- Ataxia (Loss of Balance or Coordination)
- Darkened Mucous Membrane (Mouth, Nose, Tongue)
- Muscle Tremors
- Green or Black Urine
Essential Oils That Contain Phenols, Terpenes & Ketones
What Essential Oils Contain Phenols?
Research suggests that phenols can effectively destroy most viruses, fungi and bacteria. These beneficial antiseptic and antimicrobial properties are believed to boost the immune system, so many cat owners use high-phenol essential oils as a preventative health measure.
And some essential oils contain special phenols like thymol or eugenol, which are toxic to flea larvae and other parasites. Some natural pet shampoos contain eugenol and/or thymol for this reason.
But as we’ve already learned, cats simply can’t process high levels of phenols. If too many phenols build up in a cat’s body, he could become very sick, very quickly.
That’s why it’s so important to take extra precautions when using phenol-rich essential oils. Essential oils with a high level of phenols are as follows:
- Basil (eugenol)
- Bay Laurel (eugenol)
- Cinnamon (eugenol)
- Clove (eugenol)
- Mountain savory (thymol)
- Tea tree
- Thyme (thymol)
- Ylang ylang
What Essential Oils Contain Terpenes?
Terpenes have great antiseptic properties and are responsible for many of the enticing aromas produced by essential oils. And some research suggests that essential oils containing terpenes have positive effects on respiratory tract infections, arthritis, lymphatic systems and skin parasites.
One of the most common terpenes is pinene, which is found in pine essential oil and many others. Pinene comes in two forms: alpha-pinene (which smells earthy and fresh) and beta-pinene (which is spicier and woodier).
My cats always roll in the pine mulch and resin in the spring, summer and fall, possibly self-medicating against fleas. They’ve never shown any ill effects from this behavior, but pinene is much more concentrated in essential oils than it is in pine mulch.
Cats can’t handle high concentrations of pinene, and buildup can result in liver toxicity, as it does with phenols. Additionally, pinene is prone to oxidizing, which can result in irritation of the skin and respiratory tract.
The following essential oils contain high concentrations of pinene. Be very careful with these oils and consider using ones that contain less pinene instead.
- Cypress (alpha)
- Dill (beta)
- Eucalyptus (alpha)
- Fir (alpha)
- Juniper (alpha)
- Myrtle (alpha)
- Nutmeg (beta)
- Pine (alpha)
- Rosemary (beta)
- Spruce (alpha)
Cats also have difficulty metabolizing d-limonene, a terpene found in many citrus essential oils. Though it can have energizing and anti-cancer effects in low concentrations, it’s toxic in higher concentrations.
These essential oils contain high amounts of d-limonene and should be highly diluted (or avoided altogether) if you have cats.
- Black Pepper
- Celery Seed
- Sweet Orange
What Essential Oils Contain Ketones?
Ketones have calming and analgesic properties that promote cell regeneration, decongestion and nerve health. These benefits lead many cat owners to believe that they’re safe and even healthy for cats.
But cats are much more sensitive to ketones than humans are. Felines just can’t metabolize ketones quickly enough to prevent toxic levels from building up in their bodies.
Essential oils that contain high levels of ketones can be found in the following list. To mitigate harm, dilute or avoid these oils if you have cats.
- Blue Tansy
What Essential Oils Are Safe for Cats?
So do these long lists of toxic oils mean that you should never use any essential oils around cats?
Well, not quite. You’ll need to be much more cautious than you would if you didn’t have cats, but if you do your research and dilute your oils properly, many can be used safely.
High concentrations of essential oils will harm any mammal, including humans. The key, then, is to dilute and diffuse small quantities to ensure relatively harmless levels of concentration for your cat.
If an essential oil contains phenols, then be sure that the oil is diluted to less than an 8 percent concentration level. The same goes for other toxic compounds: dilute to 20 percent for ketones, 15 percent for d-limonene and 15 percent for pinene.
And use even more caution with the following essential oils, which should be diluted down to 5 percent concentration before use:
Diffusing Is the Safest Form of Dispensing Essential Oils Around Cats
The way you use essential oils around your cat is just as important as the type of oil.
Never apply essential oil directly to your cat’s skin, even if it’s diluted, as it can cause severe irritation. And don’t allow your cat to ingest any essential oils, either — internal irritation is even worse than external irritation.
If you’re set on using essential oils around your cat, a diffuser is the way to go.
Diffusing essential oils is the safest form of dispensing essential oils around cats for many reasons:
- Diffusion allows dilution of the essential oil
- Diffusion promotes an environment that is anti-fungal, antiviral and antiparasitic
- Diffusion allows ventilation in the room
- Diffusion allows your cat to leave the room if intolerant to the scent
If you are new to diffusing essential oils with your cat, then start off by choosing essential oils that have already been tested and are known to be safe around cats. These include lavender, frankincense, copaiba and helichrysum oils.
Cats, like all animals, have their own individual preferences. So when starting a diffuser method or an essential oil not already tested with your cat, stay vigilant and watch your cat’s reaction.
If the oil is bothering your cat, he may leave the room, act irritable or appear fearful. But even if he doesn’t seem bothered, it’s still important to take all possible precautions and watch for toxicity symptoms — cats don’t always know what’s best for them.
And if you see him grimacing, that doesn’t necessarily indicate an aversion! Your cat is probably just taking the scent into his Jacobson’s organ, which is located in his mouth.
How to Diffuse Essential Oils Around Cats
Diffusion is the safest and most tolerated form of dispensing essential oils around cats.
In a diffuser, add 3 to 5 drops of essential oils, ensuring that you don’t exceed the dilution guidelines discussed earlier in this article. The diffuser can then be turned on for short periods of time until there is apparent tolerance by the cat (see this video).
When it is apparent that your cat tolerates an essential oil, then greater concentrations and periods of diffusion can be increased. Never exceed the recommended concentrations for oils containing phenols, ketones, pinene or d-limonene.
To minimize risk, diffuse only one essential oil at a time until tolerance is established. Make sure that the room is well-ventilated and that the cat has access to an exit, in case the aroma becomes overwhelming.
21 of Our Favorite Essential Oils for Cats
- Balsam Fir
- Blue Tansy
- Clary Sage
- Mountain Savory
- Palo Santo
- Roman Chamomile
Essential Oils for Cat Health
- Anxiety – Geranium, Lavender, Roman Chamomile and Valerian
- Arthritis – Copaiba, Pine, Spruce and Wintergreen
- Bleeding – Cistus, Geranium and Helichrysum
- Bones – Lemongrass, Spruce and Wintergreen
- Calming – Lavender (all animals typically respond favorably to the smell of lavender)
- Coat Health – Rosemary and Sandalwood
- Fleas & Parasites – Eucalyptus, Lemongrass and Tea Tree oil in very low concentrations (no more than 1%)
- Inflammation – Pine, Spruce and Wintergreen
- Insect repellent – Blue Tansy, Eucalyptus and Palo Santo
- Ligament/Tendons – Lavender, Lemongrass and Palo Santo
- Pain – Clove and Helichrysum
- Sinus – Eucalyptus, Myrtle and Pine
- Skin Cancer/Skin Ruptures – Clove, Frankincense, Geranium, Lavender, Melrose and Myrrh
- Ticks – Cinnamon and Peppermint
- Trauma – Lavender, Melissa, Roman Chamomile and Valerian
- Tumors/Cancer – Clove, Frankincense, Lavender and Ledum
- Worms and Parasites – Anise, Fennel, Ginger, Juniper, Lemongrass and Patchouli
- Wounds – Helichrysum and Melrose
Research reveals that cats love scent, including many of the aromas found in essential oils. And when used properly and responsibly, essential oils may have health benefits for both you and your feline friends.
A common sense approach is critical when introducing any new essential oil or aromatherapy for your cat. Research the compounds found in your oils of choice and dilute appropriately before using them around your cat.
To be extra safe, we recommend consulting your veterinarian before using a new essential oil around your cat. Your vet can test your cat’s blood and urine to establish baseline levels, which will help identify toxicity should your cat become ill.
Additionally, vets have access to medical literature and research tools that can help establish the safety of any given essential oil.
And if there’s any doubt about whether an oil is safe to diffuse around your cat, err on the side of caution. The potential benefits aren’t worth the risk to your cat’s health, so stick with known safe oils whenever possible.
Related Guides About Cats
"In ancient times cats were worshipped as gods; they have not forgotten this."
-- Terry Pratchett