Dose-confirmation studies of the cestocidal activity of pyrantel pamoate paste in horses.

This research article is about the effectiveness of pyrantel pamoate paste in treating cestode (tapeworm) infections in horses. The study confirmed the medication can eliminate A. perfoliata, a common species of tapeworm in horses, with an effectiveness of at least 95.5%.

Study Design and Methodology

• The studies were conducted at two sites in North America (Urbana, IL and Knoxville, TN) in 2001 on horses naturally infected with cestodes, which were confirmed through fecal examination.
• 42 horses were enrolled into the study—20 at Site 1 and 22 at Site 2. They were acclimated to study conditions for two weeks and then randomly allocated to one of two treatment groups—T1 got the pyrantel pamoate treatment while T2 served as untreated controls.
• The doses of pyrantel pamoate paste were determined based on the horse’s weight. These were administered orally to Group T1 horses.
• After administering the medicine, the animals were monitored by trained personnel to detect any potential adverse reactions.
• Following 10-12 days, horses were euthanized and necropsied to see the effect of the treatment. Both the contents and walls of the large and small intestines were examined for attached cestodes.

Key Findings

• At Site 1, Anoplocephala perfoliata, a species of cestode, was recovered from seven of 10 control horses and from only one of 10 horses treated with pyrantel pamoate.
• Similarly, at Site 2, cestodes were found in 10 of 11 controls and in five of 11 horses treated with the medication.
• The mean number of cestodes was significantly lower in the treated group compared to the control group at both sites.
• The calculated efficiency of pyrantel pamoate paste was 98.4% at Site 1 and 95.5% at Site 2. Therefore, overall in two dose-confirmation studies, a single oral pyrantel pamoate paste dose was found to be at least 95.5% effective against A. perfoliata in horses.

Conclusion

• The studies confirm the efficacy of pyrantel pamoate paste as a treatment for horses with naturally-acquired cestode infections, especially against the A. perfoliata species.
• With its high effectiveness of at least 95.5%, a single dose of this medicine could significantly reduce tapeworm count in horses, which demonstrates its potential in the prevention and control of tapeworm infections in the equine industry.