An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infestation in pigs

Pigs (n = 5) were infested with S. scabei var suis, and randomised to treatment at the start of peak infestation with fluazuron at a dose of 10 mg/kg/day per os for 7 days (n = 3) or no treatment (n = 2). Clinical scores, skin scrapings for mite counts and blood sampling for pharmacokinetic analysis were undertaken. Fluazuron was well absorbed in treated pigs with measureable blood levels up to 4 weeks post treatment. No adverse effects were observed. Modest acaricidal activity of the compound was observed, with a reduction in severity of skin lesions in treated pigs, as well as a reduction in number of scabies mite's early life stages.The moderate efficacy of fluazuron against scabies mites indicates a lead to the development of alternate treatments for scabies, such as combination therapies that maybe applicable for human use in the future.Scabies is an infectious skin disease caused by a microscopic mite, Sarcoptes scabiei. The number of treatments employed for this parasitic disease is very limited. The most common treatments in human and veterinary settings are topical 5% permethrin and/or systemic treatment with a macrocyclic lactone, such as ivermectin [1]. These acaricides have relatively little activity against arthropod eggs, hence multiple treatments are generally required to achieve cure. Using in-vitro, biochemical and molecular approaches, we have previously demonstrated that mites are becoming increasingly resistant to both acaricides [2-4]. The emergence of acaricide resistance in mites has highlighted the need to identify new acaricidal agents. We have previously investigated the acaricidal activity of natural product extracts of tea-tree oil and clove oil and their active components using in vitro studies of mites collected from pigs with experimental scabies infestation [5]. These studies have shown potential useful acaricidal activity of essential oils- tea-tree (Melaleuca alternifola) and clove (Eugenia caryophyllata), and their active component