Efficacy and persistent activity of moxidectin against natural Muellerius capillaris infection in goats and pathological consequences of muelleriosis.

The effect of moxidectin against natural Muellerius capillaris infection in goats was evaluated in this study. Long-acting moxidectin at a single dose of 1 mg kg(-1) body weight was administered to an entire flock (n=10) of goats. The individual faecal larval count reduction was applied as an indicator of treatment efficacy. A significant reduction (>98%) in larval counts was observed in all surveyed animals 14 days after drug administration. Moxidectin demonstrated persistent activity in this study; the mean faecal larval count reduction was 99.1% ± 1.8 on day 77 of the treatment. Macroscopic abnormalities and histological changes in the lungs of two infected goats were evident during the post-mortem examination. The pathological consequences of M. capillaris infection were observed even three months after parasite elimination. The results of this study indicate that moxidectin is a highly effective anthelmintic agent for the control of muelleriosis in goats. This drug provides animals with fifteen weeks of protections against M. capillaris reinfection.