Experimental chemotherapy in horses infected with benzimidazole-resistant small strongyles.

The research article investigates the effectiveness of different deworming drugs for horses infected with small strongyles that are resistant to benzimidazole. They found that a mebendazole and piperazine citrate combo was more effective than mebendazole alone but less effective than pyrantel embonate or dichlorvos.

Objective of the Research

• The main aim of this research was to determine the effectiveness of various deworming drugs and combinations in treating small strongyles in horses, particularly those infected with the benzimidazole-resistant strain. These parasites pose significant health risks to horses, thus necessitating effective treatment strategies.

Methodology

• The researchers carried out a series of faecal egg counts and larval cultures on infected horses present at two properties in the northwest of England. These tests confirmed the presence of benzimidazole-resistant small strongyles – a specific thread of parasitic worms.
• They then proceeded to treat these horses with mebendazole, a common anthelmintic or deworming drug. Mebendazole works by affecting the cytoplasmic microtubules within the cells of the parasites, disrupting their glucose uptake and leading to their ultimate death.
• Subsequently, they tested a trail formulation of mebendazole combined with piperazine citrate, another anthelmintic that works by paralyzing the worms and causing them to be expelled through the bowels of the horse. This was done to see if the combo could yield a greater reduction in faecal egg counts than treatment with mebendazole alone.

Results and Conclusion

• According to the findings, the combination of mebendazole with piperazine citrate did result in more significant reductions in faecal egg counts compared to mebendazole alone, implying a higher combined efficacy. This suggests that for benzimidazole-resistant strains of small strongyles, using a deworming regimen that includes both mebendazole and piperazine citrate might be beneficial.
• However, it was also noted that this combination therapy of mebendazole and piperazine citrate was significantly less effective than treating with pyrantel embonate or dichlorvos. Both of these are other types of anthelmintics, with the former working by causing paralysis in the worms and the latter working by inhibiting important enzymes in the worms leading to their death.