Essential Oils and Cats | Ashburn, VA
Essential oils are volatile, organic constituents of plants that contribute to fragrance and taste. They are extracted from plants via distillation or cold pressing. Essential oils are utilized in a variety of ways: as insecticides, in aromatherapies, personal care products (e.g., antibacterials), flavorings, herbal remedies, and liquid potpourri.
Essential oils can pose a toxic risk to household pets, especially to cats. As small, lipophilic molecules, essential oils are rapidly absorbed from the mouth, lungs, and skin. Many are then metabolized in the liver via glucuronidation and/or the P450 system. Several undergo enterohepatic recirculation as well. Because of cats' relative lack of glucuronidase, they are more susceptible to certain toxins like essential oils. Cats are also very sensitive to phenols and phenolic compounds, which can also be found in some essential oils.
Essential oils that are known to cause poisoning in cats include the non-exclusive list of oil of wintergreen, oil of sweet birch, citrus oil (d-limonene), pine oils, Ylang Ylang oil, peppermint oil, cinnamon oil, pennyroyal oil, clove oil, eucalyptus oil, and tea tree oil. Cats can also be poisoned by liquid potpourri mixtures which can contain a mixture of essential oils and cationic detergents. Clinical signs of poisoning depend on the type of product involved, the exposure scenario, route of exposure, and dose. Signs may include drooling, vomiting, tremors, ataxia, respiratory distress, low heart rate, low body temperature, CNS depression, oral ulceration, and liver failure. As with all toxins, poisoning is dose-dependent. While the toxic dose of each of these oils varies, the higher the concentration of the essential oil, the great the risk to the cat. For example, direct application of 100% tea tree oil is much more dangerous than the use of shampoo with 1% tea tree oil.
Pet owners apply essential oils to pets for a variety of reasons. Those most commonly reported to Pet Poison Helpline included the application of concentrated oils directly to the skin for ectoparasite prevention or control, skin conditions such as ringworm, 'hot spots', etc., and to the pinna or into the ear canal for treatment of infection, mites, etc. While there is research supporting antimicrobial or antiparasitic properties of various essential oils, direct application of concentrated preparations is never advised due to the risk of intoxication.
When pets are exposed to potentially toxic doses of essential oils, treatment is first focused on decontamination. For dermal exposures, this typically involves bathing with a degreasing detergent such as hand dishwashing soap or a follicle stripping shampoo to remove the product as best as possible. This will reduce the risk for both transdermal and oral exposure. In the case of oral exposures, especially to liquid potpourri, thoroughly rinsing of the mouth may be necessary. The use of emetics is generally not recommended or effective because the oils are rapidly absorbed across the mucosa or GI tract and there is a greater risk for aspiration. Activated charcoal may be a useful tool following either oral or dermal exposure because some oils are absorbed across the skin.
Following decontamination, additional treatment is largely symptomatic and supportive, depending on the displayed clinical signs and the specific oil. Treatment options may include intravenous fluids, anti-emetics, bronchodilators, oxygen therapy, GI protectants, hepatoprotectants, and cardiovascular support.
Oil Diffuser Types and Associated Health Hazards
The use of essential oils for aromatherapy can take on many forms: candles, potpourri, room sprays, direct application to the skin like perfume, and passive diffusers.
Passive diffusers work by evaporating the oil, producing a pleasant smell. Examples include reed diffusers, heat diffusers, personal evaporative diffusers such as necklace pendants or bracelets, and motorized diffusers. Cats indirectly exposed to oils via passive diffusers are not expected to have significant systemic uptake but that does not mean such exposures are innocuous.
The primary hazard to cats indirectly exposed to essential oils is for respiratory irritation with pre-existing respiratory diseases such as asthma, airborne allergies, or those chronically exposed to second-hand smoke are at greater risk for developing signs.
Inhalation of strong odors or fragrances can cause some cats to develop a watery nose or eyes, a burning sensation in the nose/throat, nausea leading to drooling and/or vomiting and difficulty breathing. Difficulty breathing in a cat is evidenced by labored breathing, rapid breathing, panting, coughing, or wheezing. It is crucial that pet owners know that NONE of these signs are normal in cats. A coughing episode in a cat can be mistaken as the cat trying to vomit up a hairball. Cats that are truly coughing typically crouch low to the ground, with little to none of the abdominal movement that is more typical of vomiting.
Cats suffering these signs need to be moved immediately into fresh air and require emergency veterinary treatment should their signs not quickly resolve.
Active essential oil diffusers have recently become quite popular. Examples include nebulizing diffusers - those with pressurized, high-speed air streams and atomizing nozzles - and ultrasonic diffusers - those in which electric current causes an instrument to emit a vibration. They differ from passive diffusers in that microdroplets or particles of oil are emitted into the air.
The droplets, although small, may still pose a risk to cats. Depending on how close the cat is to the dispenser, the essential oil microdroplets may collect on the cat's fur and be ingested via grooming. As with passive diffusers, respiratory irritation may also result.
Like oil and water, essential oils and cats really do not mix. Owners should be cautious using essential oils and diffusers in their homes and keep oils out of cats' reach. Most importantly, concentrated essential oils should never be directly applied to cats. In case of concerning exposures to essential oils, pet owners and veterinary professionals are encouraged to consult with the veterinary toxicology specialists at Pet Poison Helpline.