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

The research article studied the effect of two treatments, imidacloprid and phoxim, on horses that were infested by the chewing louse Werneckiella (Damalinia) equi. The results showed that both treatments were effective in controlling the lice infestation in the horses.

Introduction

• The researchers focused on the louse infestation in horses caused by species Werneckiella (Damalinia) equi, which is a universal problem for horse-keepers and a source of discomfort and potential disease for the horses themselves.
• Previous reports highlighted these infestations in Icelandic horses and their clinical signs, including louse-derived dermatitis.

Method

• A clinical field investigation was carried out in Iceland with naturally infested horses.
• The study aimed to compare the efficacies of two treatment solutions: imidacloprid in a 10% solution and phoxim in a 0.05% solution.
• A total of 27 horses received a one-time treatment with imidacloprid. It was applied using 16 ml of the 10% solution along the mane and on the dorso-lateral trunk of the horses.
• In contrast, 43 horses were treated twice, 14 days apart, with phoxim. The 50 ml solution was applied, in each instance, along the mane and the dorso-lateral trunk.

Results

• At the end of the 28-day study, the results showed both treatments were effective in controlling the infestation.
• Complete control of the lice was achieved in the horses that received the imidacloprid treatment.
• For the horses treated with phoxim, only a single moribund louse was found on two horses, indicating an extremely high rate of success.

Conclusion

• The research highlighted the effectiveness of both imidacloprid and phoxim in controlling and treating louse infestation in horses.
• It provides valuable information for the treatment of louse infestations in horses, especially in regions where Werneckiella (Damalinia) equi are prevalent.