Eficacy of ivermectin, moxidectin and febendazole in equine in Brazil.

This study evaluates the effectiveness of three anthelmintic drugs, fenbendazole, ivermectin, and moxidectin, in controlling horse parasites in the western part of São Paulo, Brazil. The research revealed that fenbendazole had developed resistance, while ivermectin and moxidectin were highly effective.

Research Methodology

• The study was carried out from February to December 2013 on 10 farms in the western region of São Paulo, Brazil.
• An examination of feces was conducted to determine the number of eggs per gram (EPG) as an indication of parasite infestation.
• Third-stage larvae (L3) of strongyles, a common equine parasite, were identified through coprocultures created from the feces samples.
• In addition, the researchers asked questions about each farm’s management practices and characteristics, including their parasite control measures.
• To determine the effectiveness of each anthelmintic drug, the researchers utilized a fecal egg count reduction test (FECRT). This method compares EPG count results before and after treatment.

Research Findings

• Results from the FECRT showed that fenbendazole had developed resistance among the parasites, thus lowering its efficacy.
• Ivermectin and moxidectin, on the other hand, were found to be highly effective in controlling equine parasites in the farms studied.
• The parasites present were identified as predominantly cyathostomins within the group of strongyles, particularly where deworming intervals were long.
• The survey results indicated that ivermectin was the most commonly used drug among the farmers for parasite control.

Key Takeaway

The study raises concerns about the emergence of resistance to fenbendazole among equine parasites, underscoring the need for varied and planned parasite management strategies. Additionally, this research shows the high effectiveness of ivermectin and moxidectin, thus solidifying their prominence in equine parasite management strategies.