Antiparasitic activity of parbendazole in critical tests in horses.

This research study investigated the effectiveness of parbendazole, a drug used to eradicate parasites, in horses. The results showed that the drug was effective against a range of internal parasites at varying doses, although its efficacy was inconsistent at some dosage levels and it was ineffective for stomach parasites.

Research Methodology

• The study was performed on 11 horses that were naturally infected with parasites.
• Different doses of parbendazole, ranging from 2.5 mg/kg to 30 mg/kg, were given to the horses via a stomach tube.
• Each dose level was administered to a different number of horses – 1 horse received the 30 mg/kg dose, 4 horses the 20 mg/kg dose, and so on.

Findings and Results

• The research found that parbendazole was effective against several types of parasites, including Parascaris equorum, Oxyuris equi, Strongylus vulgaris, Strongylus edentatus, and small strongyles.
• The effectiveness didn’t significantly deteriorate with lower doses, but complete clearance of P equorum required a dose higher than 2.5 mg/kg.
• Removal of Oxyuris equi was virtually 100% even at the smallest dose, though mature forms of this parasite were present only in small numbers.
• Two specific parasites, Strongylus vulgaris and Strongylus edentatus, were largely removed at all dosage levels, but the results were a bit inconsistent at intermediate doses.
• The overall removal rates for small strongyles were satisfactory, even at the smallest doses.
• However, the drug had limited or no effect on parasites residing in the stomach.
• A temporary side effect of diarrhea lasting 24 to 48 hours was observed in horses at all dosage levels. This is a common side effect of anti-parasitic medications and is often due to the die-off of the parasites.

Conclusion

• The researchers concluded that parbendazole is effective against a range of parasites in horses. However, dosage and target parasite type are important considerations for its effective use.