Effectiveness of a single application of 0.25% fipronil solution for the treatment of hirstiellosis in captive green iguanas (Iguana iguana): an open-label study

Abstract

Hirstiella spp. are common ectoparasites of captive green iguanas (Iguana iguana). Suggested treatments are empirical and some of them are of low efficacy and potentially toxic. The objective of this open-label study was to investigate the short-term efficacy and safety of a single application of 0.25% fipronil solution for the treatment of hirstiellosis. The skin of 50 green iguanas was thoroughly examined with the aid of bright light and magnifying lenses. A total of 21 iguanas were found to be infested, harbouring 1-24 mites (median: 5). All 35 mites collected from 17 iguanas were identified as Hirstiella sp. Both infested and non-infested lizards, sharing the same enclosure, were carefully wiped with 0.25% fipronil solution. The safety and the efficacy of the treatment were evaluated after 2 days in 47/50 (94%) and 7 days in 29/50 (58%) iguanas. Compared with pre-treatment levels, the parasitic load did not changed significantly on the second day but was significantly lower on day 7 (P = 0.006). No adverse reactions were noticed. Based on these results a single whole-body application of 0.25% fipronil solution can be considered a safe and effective treatment for the reduction of parasitic burden in captive green iguanas infested by Hirstiella sp. mites.