The sensitivity of Demodex canis (Acari: Demodicidae) to the essential oil of Melaleuca alternifolia – an in vitro study

Abstract

The essential oil of the Melaleuca alternifolia (Maiden & Betche) (tea tree oil) has been effective in previous studies, in the treatment of infestation by Demodex mites in humans. The present study aimed at evaluating the in vitro acaricidal effect of this herbal medicine on Demodex canis. For the parasitological examination, samples were collected from a dog’s skin and examined using optical microscopy. Only samples with intact mites and with evident movement of chelicerae and tarsi were selected. Twenty-one samples were tested with the oil, in seven different concentrations: 100%; 50%; 25%; 12.5%; 6.25%; 5.0% and 3.13%. Three samples were tested with the positive control amitraz, and three with the negative control neutral shampoo. The interval between the time the solution was added and the moment the movement of the last mite ceased defined the survival time in the sample. By comparing the times at different concentrations and controls, the results showed that the higher the concentration of the oil, the more quickly its lethal effect occurred, and that the survival times in the controls were longer than in the different concentrations of melaleuca oil.

Antiparasitic Activity of Tea Tree Oil (TTO) and Its Components against Medically Important Ectoparasites: A Systematic Review

“…Our review found that TTO and its components (mainly T4O) can completely eradicate Demodex mites and reduce mite-related symptoms without any serious AEs, as evidenced by multiple studies (Tables 1 and 2). The efficacy reported in clinical studies was consistent with the in vitro results of laboratory-based studies and results reported for veterinary Demodex mites (D. canis), where the survival time of mites was 8-100 min for TTO (3.125-100%) [122]. Demodex mites (Demodex folliculorum and D. brevis) are the most common permanent ectoparasites in humans, infesting the pilosebaceous unit of the face and scalp skin to cause demodicosis [7,123].…”