Anthelmintic treatment of equids: capabilities and limitations. Critical tests of nine anthelmintic agents on ponies.

A number of good anthelmintic drugs are currently available which eliminate gastrointestinal nematodes of equids with over 90% success. This is shown by comparing results of critical tests conducted with 9 anthelmintic agents on ponies using the following dosages: 19 mg/kg for Pyrantel embonate, 10 mg/kg for Oxfendazole, 10 mg/kg for Mebendazole, 5 mg/kg for Albendazole, 40 mg/kg for Dichlorvos, 44 mg/kg for Thiabendazole, 7.5 mg/kg, for Fenbendazole, 20 mg/kg for Cambendazole and 7 mg/kg for Parbendazole. From 6 to 9 ponies were treated with each of these anthelmintic agents. Based on total activity of various parasites involved, there was no significant difference in activity of any of the nine agents. With respect to Trichonema spp., or small strongyles, which are most numerous and most common in equids, statistical analysis enabled all nine products to be classified into three groups as follows: group 1, with the most active being Oxfendazole and Pyrantel embonate; group 2; including Thiabendazole, Mebendazole, Albendazole and Cambendazole; group 3, with Parbendazole, Fenbendazole et Dichlorvos. Results with large strongyles sometimes vary quite significantly. Dichlorvos and Pyrantel embonate should be recommended against Strongylus spp.; Mebendazole and dichlorvos against pinworms; Cambendazole against Strongyloïdes westeri; Pyrantel embonate, Cambendazole and Dichlorvos against Parascaris equorum; and Dichlorvos, Mebendazole with Trichlorfon and Pyrantel embonate with Trichlorfon against bots. No activity against Trichostrongylus axei, Anoplocephala spp. was noted with any of the nine agents tested.