Clinical and Parasitological Evaluation of Ivermectin and Ivermectin + Pyrantel Against Oxyuris Equi in Equines.

This research article details a study that compared the effectiveness of the drugs ivermectin (IVM) and a combination of ivermectin and pyrantel pamoate (PYR) in treating pinworm infections in horses. The findings revealed that the combination of IVM and PYR was more successful than IVM alone in controlling the parasite and reducing related clinical symptoms.

Objective and Approach

• The study was initiated because of the growing concern about the equine pinworm becoming a problem due to reports of control failure. This study aimed to compare the effects of IVM alone and a combination of IVM and PYR.
• To measure this, thirteen horses with parasitological positive tests were treated orally with IVM.
• Their response on the basis of therapeutic efficacy, clinical recovery, and egg reappearance period (ERP) were examined.
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  • In instances where ERP was shorter than the pre-patent period (PPP – the period between infection and first detectable eggs), a second treatment option using a combination of IVM and PYR was used.
  • The same evaluation parameters were again applied.

Results

• The study findings showed that the therapeutic efficacy of IVM and PYR combined was 100%, while for IVM alone, it was 53.84%.
• The mean ERP was found to be less than the PPP for both treatment options, with 77.55 days for IVM and PYR combined and 50 days for IVM alone.
• The study also observed that the presence of egg mass was consistently associated with a least one clinical sign.
• The results indicated a greater reduction in the number of clinical signs per animal from day 0 to day 30 in horses treated with a combination of IVM and PYR compared to those treated with IVM by itself.
• The study also revealed that horses treated only with IVM were 4.5 times more likely to present clinical symptoms 30 days after treatment compared to those treated with the IVM and PYR combination.

Conclusion

• The clinical and parasitological evaluation led to the conclusion that the combination of IVM and PYR was notably more effective than IVM alone in controlling the equine pinworm Oxyuris equi.
• The study also found a negative correlation between ERP and the number of clinical signs at 30 days in the horses treated with IVM.
• These results underline the importance of using a combination of IVM with PYR in the treatment of pinworm infections in horses.