The document discusses various anthelmintic drugs used to treat helminth infections in animals. It provides details on the mechanisms of action, pharmacokinetics, clinical uses, adverse effects and contraindications of commonly used anthelmintics including albendazole, mebendazole, thiabendazole, pyrantel pamoate, piperazine, niclosamide, diethylcarbamazine, ivermectin, and bithionol. These drugs act by paralyzing or killing intestinal worms and parasites through various mechanisms such as inhibiting microtubule synthesis, interfering with metabolism, or increasing chloride influx in parasites.