Natural infestation of the chewing lice (Werneckiella equi) on horses and treatment with imidacloprid and phoxim

Abstract

Infestation with the chewing louse (Werneckiella (Damalinia) equi) can be found on horses world-wide. Louse infestations, including clinical signs of louse-derived dermatitis, are known from Icelandic horses. A clinical field investigation was conducted in Iceland using horses with natural louse infestations to evaluate the efficacy of imidacloprid in a 10% solution in comparison with phoxim in a 0.05% solution. A total of 27 horses received a single imidacloprid treatment using 16 ml of the 10% solution along the mane and on the dorso-lateral trunk. A further 43 horses were treated twice, 14 days apart, with phoxim, using 2 x 50 ml solution applied along the mane and the dorso-lateral trunk. At the final evaluation on day 28, complete control of the lice was obtained for the imidacloprid treated horses and only a single moribund louse was found on two horses treated with phoxim.

Dermatological and parasitological evaluation of infestations with chewing lice (Werneckiella equi) on horses and treatment using imidacloprid

“…Further variables for a topical-applied compound are the behavioural factors of the animal species. For the treat- (Mencke et al 2004) demonstrated the efficacy of imidacloprid against lice. A dose of 16 ml of the 10% imidacloprid solution was effective to clear an existing lice infestation.…”

“…Housing of horses was described previously by Mencke et al (2004). The 93 horses included into this study belonged to a total of 158 horses out of 15 individual stables.…”

“…In the study presented here, the dermatological signs of lice infestation on horses is thoroughly investigated. The use of imidacloprid as a therapeutic compound in lice control on horses has been reported previously (Mencke et al 2004). In the present study, however, the impact of treatment, using different concentrations of imidacloprid, is studied and clinical manifestations are observed.…”

“…Lice as host-specific permanent parasites on horses are reported to be widespread and lice parasitism is of clinical significance in equine medicine. Infestations may cause irritation, unthriftiness and dermatological lesions (Mencke et al 2004). In the study presented here, the dermatological signs of lice infestation on horses is thoroughly investigated.…”

The efficacy of four common anthelmintic drugs and traditional Chinese medicinal plant extracts to control Dactylogyrus vastator (Monogenea)

“…However, under in vivo conditions we found that the anthelmintic effect was only moderate. Meyer-Kuhling et al (2007) reported that just a single administration of phoxim killed 99.1% of red mites, while previous studies have reported that the majority of lice and fleas treated with phoxim were killed at the end of treatment (Larsen et al, 2005;Mencke et al, 2004). Hence, the anthelmintic efficacy of phoxim on Dactylogyrus appeared far less than its effects on other genera of ectoparasites.…”