Evaluation of the efficacy and safety of two formulations of pyrantel pamoate in cats.

The efficacy of paste and granule formulations of pyrantel pamoate against concurrent infections of Toxocara cati and Ancylostoma tubaeforme in cats was examined in a controlled trial. Three groups of 8 cats received either no medication (controls) or pyrantel pamoate in paste or granule formulations at a dosage of 20 mg/kg of body weight. After administration of the paste formulation, fecal egg counts of A tubaeforme and T cati were decreased by 98.6 and 96.4%, respectively, and 100% of hookworms and 93.5% of ascarids were removed from the intestine. After administration of the granule formulation, fecal egg counts of A tubaeforme and T cati were decreased by 99.4 and 78.2%, respectively, and 100% of adult hookworms and 88.9% of ascarids were removed. All reductions of egg counts and worm numbers were significant (P less than 0.01). The clinical safety of pyrantel pamoate was evaluated in 4- to 6-week-old kittens. Three groups of 10 kittens received either no medication (controls) or pyrantel pamoate in paste or granule formulations at the rate of 100 mg/kg for 3 consecutive days. Adverse effects were not observed in young kittens following administration of the high dose of pyrantel pamoate.