Effectiveness of ivermectin in the treatment of equine Parascaris equorum and Oxyuris equi infections

Abstract

Fifteen horses harboring naturally acquired, patent Parascaris equorum and Oxyuris equi infections were equally allotted to 3 treatment groups given (1) injectable vehicle; (2) injectable ivermectin at the dose rate of 200 microgram/kg of body weight; and (3) injectable ivermectin at the rate of 300 microgram/kg. All treatments were given IM in the neck. All animals were killed 14 days after treatment and examined for the targeted nematodes. Regardless of dose rate, ivermectin proved 100% effective in the removal of adult O equi and P equorum infections. Levels of immature P equorum were decreased by 98.5% in both ivermectin-treated groups. Oxyuris equi 4th-stage larval injections were decreased by 95.7% and 99.9% by the 200 and 300 microgram/kg ivermectin treatments, respectively. Adverse reactions to the injections of drug were not seen.