Clinical and mycological evaluation of an herbal antifungal formulation in canine Malassezia dermatitis

Abstract

Objective: Malassezia pachydermatis is a common cause of more widespread dermatitis in dogs (CMD). Recurrences are common, and this disorder can be very troubling for both dogs and for the pet owner.

Material and methods: The treatment of 20 dogs affected by dermatitis due to M. pachydermatis, with Malacalm(®), a commercially available mixture consisting of essential oils (Citrus aurantium 1%, Lavandula officinalis 1%, Origanum vulgare 0.5%, Origanum majorana 0.5%, Mentha piperita 0.5% and Helichrysum italicum var. italicum 0.5%, in sweet almond oil and coconut oil) is reported. The effectiveness of the whole mixture, of component essential oils and of their more represented compounds against clinical isolates was evaluated by a microdilution test. Twenty animals were topically administered the mixture twice daily for 1 month. Ten animals were treated with a conventional therapy based on ketoconazole 10mg/kg/day and chlorhexidine 2% twice a week for 3 weeks. At the end of both treatments animals significantly improved their clinical status. Adverse effects were never noticed. Follow-up visit performed on day 180th allowed to observe a recurrence of clinical signs in all the subjects treated conventionally, while not significant clinical changes were referred in dogs treated with Malacalm(®). The overall MIC value of Malacalm(®) was 0.3%. O. vulgare showed the lowest minimum inhibitory concentrations (MIC), being active at 0.8%, followed by M. piperita (1%), O. majorana (1.3%), C. aurantium (2%) and L. officinalis (4%) while H. italicum did not yield any antimycotic effect up to 10%. Active major compounds were thymol, carvacrol, p-cymene, 1,8-cineol, limonene and menthol.

Conclusion: The phytotherapic treatment achieved a good clinical outcome, and no recurrence of skin disorders on day 180th was recorded. This herbal remedium appeared to be a safe tool for limiting recurrences of CMD.

Keywords: Essential oils; Huiles essentielles; In vitro susceptibility; In vivo treatment; Malassezia pachydermatis; Sensibilité in vitro; Traitement in vivo.