Comparative performance of macrocyclic lactones against large strongyles in horses.

The study assesses the effectiveness of various macrocyclic lactone formulations in controlling gastrointestinal nematodes in horses. The results varied among different drugs and the generic ivermectin 4% paste proved to be less effective than the others.

Research Goals and Methodology

• The researchers aimed to investigate the comparative effectiveness of several macrocyclic lactone formulations. These included abamectin, ivermectin, moxidectin, ivermectin in combination with praziquantel and ivermectin in combination with pyrantel.
• This study was carried out on a stud farm in southern Brazil, focusing specifically on how effective these drugs are at controlling gastrointestinal nematodes in horses.
• They also tested a generic pharmaceutically produced paste containing ivermectin 4%.

Key Findings and Conclusions

• The research found that different formulations of avermectins had varying levels of efficacy, measured by the reduction of EPG (eggs per gram).
• The specific level of drug effectiveness also varied for different large strongyles including Strongylus edentatus, S. equinus, and S. vulgaris.
• Importantly, the study shows that the generic ivermectin 4% paste was less effective in controlling the specified strongyles when compared to the other conventional drugs used in the research. This suggests that generic versions may not provide the same level of parasite control as branded options.

Implications of the Research

• This research may influence how vets and horse owners approach nematode control among their horses, particularly in suggesting that cheaper generic options may not provide the same efficacy as more traditional, branded drugs.
• These findings also suggest that more research is needed to further understand the relationship between drug formulation and efficacy, potentially leading to improvements in equine deworming strategies.