pyrantel and oxibendazole

Forty 11- to 12-week-old helminth-naive Beagles were categorized by sex and weight and randomly assigned to 4 treatment groups (group 1, ivermectin/pyrantel pamoate; group 2, milbemycin oxime; group 3, untreated control; group 4, diethylcarbamazine/oxibendazole). Each pup was inoculated PO with approximately 100 infective Ancylostoma caninum larvae and 100 larvated Toxocara canis eggs on day 0, and repeatedly at 7-day intervals thereafter until day 56. Administration of anthelmintics also began on day 0, and subsequent treatments were administered according to label recommendations at 30-day intervals (groups 1 and 2) or daily (group 4) for a period of 90 consecutive days. Body weight and A caninum and T canis fecal egg counts were measured at weekly intervals, and clinical observations of health status were conducted twice daily. Pups were euthanatized on day 90, and total gastrointestinal worm burdens were determined. Compared with mean A caninum egg counts of group-3 control pups, egg counts in group-1 pups were significantly (P < or = 0.0001) lower on every sampling days 35, 42, 49, 63, 70, 77, and 84, and were consistently the highest of all treated groups, and egg counts of group-4 pups were significantly (P < or = 0.0001) lower on every sampling date from day 14 to day 90, and were consistently the lowest of all treated groups. Compared with mean A caninum egg counts of group-3 pups, egg counts in group-1 and group-2 pups were lower by 97.8 and 90.8%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Age Factors; Analysis of Variance; Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Benzimidazoles; Diethylcarbamazine; Dog Diseases; Dogs; Drug Therapy, Combination; Female; Ivermectin; Macrolides; Male; Parasite Egg Count; Pyrantel; Toxocariasis

Antiparasitic activity of several compounds was evaluated over a long period (about 25 years) in the same flock of sheep. Haemonchus contortus was of special interest, including its relation to drug resistance, especially to thiabendazole and other benzimidazoles, in addition to phenothiazine. Eleven compounds were evaluated in 15 controlled tests, done between 1966 and 1989 in naturally infected lambs (n = 145) born and raised on the same pasture. Sheep were first placed on the pasture in 1962, and a few more were added thereafter. Internal parasites in these sheep were classified in 3 general categories: indeterminate exposure to parasiticides; H contortus, resistant to thiabendazole; and H contortus, resistant to phenothiazine. The parasitic infections probably became more homogeneous after several years because of few introductions of outside sheep after initial establishment of the flock. Activity against naturally acquired internal helminths was evaluated for cambendazole (CBZ: dosage, 20 mg/kg of body weight), fenbendazole (FBZ: 5 or 7.5 mg/kg), mebendazole (MBZ: 10 mg/kg); oxfendazole (OFZ: 3.5 or 10 mg/kg), oxibendazole (OBZ: 10 mg/kg); parbendazole (PBZ: 15 mg/kg), phenothiazine (PTZ: 550 mg/kg); pyrantel pamoate (PRT: 25 mg base/kg), tetramizole (TET: 15 mg/kg); thiabendazole (TBZ: 30 or 44 mg/kg), and trichlorfon (TCF: 100 mg/kg). Thiabendazole was used more often (9 tests) than the other compounds. Thiabendazole was more active against mature H contortus in later years than when first used in 1966, although it was never 100% effective. Efficacy against immature H contortus for TBZ did not exceed 86%. Activity against immature and mature stages of this parasite was good overall for the other benzimidazoles.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aging; Animals; Anthelmintics; Benzimidazoles; Cambendazole; Drug Combinations; Fenbendazole; Haemonchiasis; Mebendazole; Parasitic Diseases; Parasitic Diseases, Animal; Pyrantel; Sheep; Sheep Diseases; Tetramisole; Thiabendazole; Trichlorfon