Levamisole: An antihelminthic drug that has been tried experimentally in rheumatic disorders where it apparently restores the immune response by increasing macrophage chemotaxis and T-lymphocyte function. Paradoxically, this immune enhancement appears to be beneficial in rheumatoid arthritis where dermatitis, leukopenia, and thrombocytopenia, and nausea and vomiting have been reported as side effects. (From Smith and Reynard, Textbook of Pharmacology, 1991, p435-6)Antinematodal Agents: Substances used in the treatment or control of nematode infestations. They are used also in veterinary practice.Pyrantel: A depolarizing neuromuscular-blocking agent, that causes persistent nicotinic activation resulting in spastic paralysis of susceptible nematodes. It is a drug of second-choice after benzimidazoles for treatment of ascariasis, hookworm, and pinworm infections, being effective after a single dose. (From Smith and Reynard, Textbook of Pharmacology, 1992, p920)Furylfuramide: Used formerly as antimicrobial food additive. It causes mutations in many cell cultures and may be carcinogenic.Ascaris suum: A species of parasitic nematode usually found in domestic pigs and a few other animals. Human infection can also occur, presumably as result of handling pig manure, and can lead to intestinal obstruction.Bephenium Compounds: Analogs or derivatives of bephenium (N,N-dimethyl-N-(2-phenoxyethyl)benzenemethanaminium).Anthelmintics: Agents destructive to parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal.Drug Contamination: The presence of organisms, or any foreign material that makes a drug preparation impure.Veterinary Drugs: Drugs used by veterinarians in the treatment of animal diseases. The veterinarian's pharmacological armamentarium is the counterpart of drugs treating human diseases, with dosage and administration adjusted to the size, weight, disease, and idiosyncrasies of the species. In the United States most drugs are subject to federal regulations with special reference to the safety of drugs and residues in edible animal products.Agranulocytosis: A decrease in the number of GRANULOCYTES; (BASOPHILS; EOSINOPHILS; and NEUTROPHILS).Oesophagostomum: A genus of nematodes of the superfamily STRONGYLOIDEA, parasitic in the intestines of animals. The adults are usually free in the intestinal lumen; the larvae encyst in the wall.Oxyuroidea: A superfamily of parasitic nematodes consisting of several genera. ENTEROBIUS, which occurs in humans, and Oxyuris, which occurs in horses, are two of the most common. Other genera are: Skrjabinema, Passalurus, Dermatoxys, and Probstmayria.Oxyuriasis: Infection with nematodes of the superfamily OXYUROIDEA.