Eprinomectin treatment of psoroptic mange in hunter/jumper and dressage horses: a prospective, randomized, double-blinded, placebo-controlled clinical trial.

This research sought to determine the effectiveness of a topical solution called eprinomectin for treating psoroptic mange in horses, through a double-blinded and placebo-controlled clinical trial.

Research Design

• The investigation followed a prospective, double-blinded, placebo-controlled clinical trial format. This means that the trial was designed to observe outcomes or events that have not yet occurred and both the investigators and participants were unaware of the treatment each horse was receiving, assuring bias was minimized.
• A total of 24 privately owned hunter/jumper and dressage horses diagnosed with psoroptic mange, evident through physical findings and skin scraping results, were admitted into the study.
• The horses were split into two groups with random allocation: one group received the treatment with eprinomectin, while the other group formed the control group and received a placebo (purified water).
• The enactment of the eprinomectin treatment consisted of a pour-on solution administered at a dose of 500 micrograms per kilogram of body weight, once a week for four applications.

Measurement and Analysis

• At the start, during, and at the end of the treatment period, clinical evaluations and skin scrapings were performed by the same veterinary investigator. This approach was important to ensure consistency in the collected data.
• The presence or absence of viable mites in the horses showcased the efficacy of eprinomectin, both clinically and parasitologically.
• The researchers collected skin scrapings for psoroptic mites on days 7, 14, 21, 28, and 40 as part of the follow-up routine.
• Fisher’s exact test (a statistical test used when sample sizes are small) was utilized in evaluating differences between the eprinomectin treatment and placebo groups regarding the number of horses free from mites (cure rates) on each assessment date.

Results and Conclusion

• The results revealed that horses treated with eprinomectin were significantly less likely to exhibit P. equi mites upon skin scraping when compared to the placebo group (p<0.01).
• In conclusion, the study determined that eprinomectin proved to be both an effective and safe therapy against natural infestations of P. equi in the sample population of horses.