Prevalence and treatment of tapeworms in horses.

The research article is about understanding the prevalence of tapeworms in horses in Southern Ontario and comparing the effectiveness of three drugs—pyrantel pamoate, niclosamide, and mebendazole—in treating the infestation.

Identification of Tapeworm Prevalence

• The researchers looked into the fecal samples of 580 horses of various breeds, ages, and sexes from 24 different locations to study the prevalence of the tapeworm Anoplocephala perfoliata.
• The findings showed a prevalence rate of 13.6%. However, the researchers argued that the true rate could be much higher, and they discussed the factors that might contribute to any underestimation of the prevalence rate.
• In addition, the article provided an overview of the life cycle of tapeworms in horses and compared two flotation techniques used in diagnosing A. perfoliata eggs in feces.

Ineffective Dosing of Drugs

• This study also assessed the effectiveness of three drugs—pyrantel pamoate, niclosamide, and mebendazole—in treating tapeworm infestation in horses through field and critical trials.
• It was found that pyrantel base (a form of pyrantel pamoate) and niclosamide were efficacious in field trials in eliminating the terminal egg-bearing segments of the tapeworm when administered at doses of 6.6 and 50 mg/kg respectively. But their overall efficacy in critical trials was poor, with success rates of 15% and 5.6% respectively.
• These results suggest that, at these dosages, the drugs did not significantly affect the entire tapeworm.

Effective Dosing of Pyrantel Pamoate

• However, when pyrantel base was administered at doses of 13.2 and 19.8 mg/kg—twice and three times the recommended dose for treating nematodes (another class of worms) respectively—the efficacy increased to 97.8% and 100%.
• This evidence suggested that a dosage of 13.2 mg of pyrantel base per kg of body weight is effective in treating tapeworms in horses.

Implications of Findings

• One major implication of the study is the need for dose titration studies for niclosamide to find out the most effective dose for treating tapeworm infection.
• In contrast, mebendazole was found to be ineffective even at dosages of 35.2 mg/kg, which is up to four times the usual dosage used to treat nematodes.