A clinical trial of ivermectin against eyeworms in German Shepherd military working dogs.

OBJECTIVE

To determine if monthly ivermectin was efficacious in reducing the observed incidence of eyeworms over a period of 2 months as compared with normal husbandry practices in a population of Republic of Korea Army military working dogs (MWDs).

METHODS

Prospective observation of 114 German Shepherd MWDs in a randomized, double-blind, controlled clinical trial. MWDs were randomly assigned to either a treatment group receiving a monthly dose of 0.2 mg/kg BW ivermectin orally, or to a control group given an equivalent dose volume and frequency of a saline placebo. A quantitative numerical count of eyeworms found in the eyes of MWDs was conducted at 25-day intervals.

RESULTS

The prevalence of eyeworms in the treatment group went to zero at 25 days and remained lower at 50 days (5%) than baseline (24%). Prevalence in the controls remained approximately constant over all treatment times (14% to 18%).

CONCLUSION

Although ivermectin does not prevent dogs from being infected with eyeworms, the study suggests that ivermectin administered orally at a dose of 0.2 mg/kg every 3 weeks significantly reduces the prevalence of Thelazia species eyeworms in dogs.