Efficacy of two extra-label anthelmintic formulations against equine strongyles in Cuba.

This study examines the effectiveness of two types of deworming drugs not typically used for horses, but re-purposed from swine and ruminants, in combating equine strongyles (a type of parasite) in Cuba. The results indicate that one drug, ivermectin, was completely effective, while the other, albendazole, showed reduced effectiveness in some cases, warranting further investigation.

Background and Objectives

• The problem examined in this research revolves around the increasingly high resistance to deworming drugs among equine cyathostomin parasites, which are common in grazing horses and can cause severe intestinal diseases.
• Because Cuba does not sell anthelmintic products specifically for horses, the efficacy of swine and ruminant anthelmintic formulations was tested in this study.

Methodology

• The study made use of a fecal egg count reduction test to evaluate the effectiveness of a swine, ruminant, and carnivore formulation of ivermectin and a ruminant formulation of albendazole.
• Nine horse farms in Camagüey province, Cuba were involved, including a total of 149 horses.

Results

• The albendazole was less effective on five of the nine farms, while there were no detected signs of reduced efficacy on the remaining four farms. Depending on the farm, the efficacy ranged from 41.7% to 100%.
• Post-treatment testing found cyathostomin larvae on all farms. It is important to note that large strongyle larvae were detected on all farms before the treatment began.
• The ivermectin formulation was found to be completely effective on all farms, showing 100% efficacy.

Conclusions and Further Work

• The paper concludes that the ruminant and swine anthelmintic products had varying degrees of success. Ivermectin consistently showed full efficacy, while albendazole’s effectiveness was reduced in some cases.
• Further research is needed to determine whether the reduced efficacy of albendazole is due to true resistance in the parasites or whether it is related to the specific characteristics of the pelleted formulation used in this study.