Resumen de Concentrated tea tree oil toxicosis in dogs and cats: 443 cases (2002�2012)
Objective�To determine the frequency, types, and severity of clinical signs; geographic distribution; and treatment information associated with toxicosis caused by 100% tea tree oil (TTO) in dogs and cats in the United States and Canada.
Design�Retrospective case series.
Animals�337 dogs and 106 cats with evidence of exposure to 100% TTO.
Procedures�10-year incident data were retrieved from the ASPCA Animal Poison Control Center database from January 2002 to December 2012. Only evidenced or witnessed incidents assessed as toxicosis or suspected toxicosis were included. Signalment, amount of TTO used, intention of use, and outcome information were evaluated. Severity of illness and correlations with breed, sex, age, and weight were determined.
Results�TTO was intentionally used in 395 of 443 (89%) animals. The amount used ranged from 0.1 to 85 mL. Incidents were reported from 41 states, the District of Columbia, and 4 Canadian provinces. Exposure route was cutaneous in 221 (50%) animals, cutaneous and oral in 133 (30%), and oral in 67 (15%). Clinical signs developed within 2 to 12 hours and lasted up to 72 hours. The most common signs were increased salivation or drooling, signs of CNS depression or lethargy, paresis, ataxia, and tremors. A significant association with severity of illness was found for age and weight, with higher prevalence of major illness in younger and smaller cats.
Conclusions and Clinical Relevance�Intentional or accidental use of 100% TTO in dogs or cats caused serious signs of CNS depression, paresis, ataxia, or tremors within hours after exposure and lasting up to 3 days. Younger cats and those with lighter body weight were at greater risk of developing major illness.
Tea tree oil, also known as Australian tree tea oil or melaleuca oil, is obtained by steam distillation of the freshly harvested leaves of Melaleuca alternifolia trees. Approximately 2% of the weight of the leaves can be harvested as oil.1,2,a The tree is native to Spain, Portugal, and Australia and has been introduced to the southern United States, especially Florida.a Tea tree oil is a complex mixture of approximately 100 components. This mixture has terpene-like odor, is colorless or pale yellow, and consists of 50% to 60% terpenes of various types, mainly cymene, terpinene, pinene, cineole, and higher alcohols.1,3,4,a Tea tree oil is known to have bactericidal and fungicidal properties and is used topically in humans and other animals for various skin conditions such as acne, boils, burns, corns, gingivitis, herpesvirus infections, impetigo, insect bites, lice, oral ulcers, miliaria, dermatophytosis, skin and vaginal infections, oral candidiasis, and tonsillitis.1,a The oil has been added to baths or vaporizers to help treat respiratory tract disorders. It has also been used in perfumes and aromatherapy. It is marketed in toothpaste, soap, lotion, and skin cream. The oil is marketed in health food stores as an antiseptic, fungicide, and skin care agent. Internal use has also been recommended by herbalists for the treatment of parasitic diseases, and inhalation of TTO in steam has been recommended for the treatment of sinus and throat infections. In the early 1900s, TTO was used in surgery and dentistry and for skin injuries.a In veterinary medicine, TTO is marketed for use on dogs, cats, ferrets, and horses for cleaning hair, healing hotspots, and treating some skin allergies. The concentration of TTO used in most skin care products is low and may vary from 0.1% to 1.0%.2 Undiluted TTO can be used topically in humans by most individuals without adverse effects.4 Animal owners sometimes knowingly or accidently use 100% TTO to treat various skin conditions in their dog or cat. Despite its widespread availability and use, there is a paucity of safety and toxicosis information about TTO in dogs and cats. The purpose of the study reported here was to review toxicosis incidents resulting from the use of 100% TTO in dogs and cats reported to the ASPCA APCC from January 2002 to December 2012, focusing on clinical signs (onset time, types, frequency, duration, and severity), epidemiological information, and treatment
