Butyl chloride is an alkyl halide. It is used as a butylating agent in organic synthesis, e.g., in the manufacture of butyl cellulose. n-Butyl chloride is a veterinary antiparasitic (anthelmintic) drug. It is used for the removal of ascarids and hookworms from dogs and cats. n-Butyl chloride is marketed under tradenames NBC Kaps Wormer for dogs, Happy Jack Worm for dogs; Sergeants Sure Shot Capsules for cats and dogs.

Thiacetarsamide is a drug containing trivalent arsenic. In the USA it was used for the treatment of Heartworm Infection in dogs and cats under tradename Caparsolate, however, it was discontinued because of the availability of safer alternatives. The mechanism of action for thiacetarsamide is modulation of glucose uptake and metabolism; inhibition of glutathione reductase, and alteration of the structure and function of the surface of the intestinal epithelium of the parasites.

Destomycin A is an aminoglycoside antibiotic and is reported to have antibacterial and anthelmintic activity. It has an antibacterial effect on Gram-positive bacteria, Gram-negative bacteria, and fungi. The mode of action of destomycin A is the inhibition of polypeptide synthesis in cells of Escherichia coli and stimulation of adenylate cyclase in several animal tissues. Destomycin A is added to feed for pigs and chickens to prevent parasitic infection of Ascaris suum (the mechanism of action involves inhibition of vitelline coat formation of the parasite eggs.)

Dibutyltin dilaurate (DBTDL) is an organotin compound that is used as a catalyst for polyurethane production from isocyanates and diols. Dibutyltin dilaurate improves the drying of chemically curing systems favoring the isocyanate/polyol reaction over other side reactions such as isocyanate/water. DBTL can be used to aid the curing process of polyurethanes, silicone resins, RTV silicone resins and silane modified polymers. Dibutyltin dilaurate was used for the removal of large roundworms, cecal worms, and several species of tapeworms from chickens and turkeys. Based on animal studies, prolonged or repeated overexposure to Dibutyltin dilaurate may affect the developing fetus, blood, and thymus. Overexposure to Dibutyltin dilaurate may also cause central nervous system effects.

Emodepside is a semi-synthetic product (originated by Astellas and out-licensed to Bayer for animal and human use); its precursor is synthesized by a fungus living in the leaves of Camellia japonica. It is a potent antihelminthic drug used in combination with praziquantel (as Profender®) and in combination with toltrazuril (as Procox®) for the treatment of parasitic worms in cats and dogs. Emodepside, a semi-synthetic derivative of PF1022A, belongs to a new class of anthelmintic drugs, the cyclooctadepsipeptides, and shows good efficacy against macrocyclic lactone-, levamisole- or benzimidazole-resistant nematode populations. Although putative receptors for emodepside have already been discovered, its mode of action is still not fully understood. It has being suggested that GABA(A)-receptor UNC-49 is associated with the emodepside mode of action. It has also being shown that Emodepside binds to a presynaptic latrophilin receptor in nematodes. The following presynaptic signal transduction occurs via activation of Gqalpha protein and phospholipase-Cbeta, which leads to mobilization of diacylglycerol (DAG). DAG then activates UNC-13 and synaptobrevin, two proteins which play an important role in presynaptic vesicle-functioning. This finally leads to the release of a currently unidentified transmitter. The transmitter (or modulator) exerts its effects at the postsynaptic membrane and induces a flaccid paralysis of the pharynx and the somatic musculature in nematodes.

Toltrazuril (Baycox, Procox, Tolcox, Toltrazuril) is a veterinary drug approved in Europe for the treatment of parasitic infections caused by roundworms and coccidia. In dogs it is used in combination with emodepside (Procox).

Nitroscanate (trade name Lopatol) is a medium-spectrum anthelmintic used on dogs and cats. It is available in the form of tablets for oral administration. It is not used on livestock. Nitroscanate is effective against the major gastrointestinal roundworms (nematodes) of dogs and cats (e.g.Toxocara canis, Toxocara cati, Ancylostoma spp, Uncinaria stenocephala) and tapeworms (e.g. Dipylidium caninum, Echinococcus granulosus, Taenia spp, etc.). The molecular mode of action of nitroscanate has not been elucidated. It is assumed that it acts as an uncoupler of the oxidative phosphorylation in the cell mitochondria, which disturbs the production of ATP, the cellular "fuel". This impairs the parasites motility and probably other processes as well.

Monepantel (trade name Zolvix) is a new oral anthelmintic drug from a group of amino-acetonitrile derivatives with broad-spectrum activity against gastrointestinal nematodes of sheep, including adults and L4 larvae of the most important species. Monepantel have a novel mode of action involving a unique, nematode-specific clade of nicotinic acetylcholine receptor (nAChR) subunit ACR-23. Monepantel acts as a positive allosteric modulator of this receptor subunit, which is forced to open on stimulus but cannot close again, resulting in a constant uncontrolled flux of ions and finally in a depolarization of muscle cells leading to paralysis, spasmodic contractions of the anterior portion of the pharynx and ultimately death of adult nematodes. Monepantel-exposed C. elegans also exhibited molting defects and large vacuoles, characteristic for necrosis, are developed. Some nematode species lack ACR-23/MPTL-1 and predicted them to be Monepantel insensitive. Caenorhabditis nematodes equipped with ACR-23/MPTL-1 receptor subunits were found susceptible to Monepantel, whereas Pristionchus pacificus, closely related to these worms but lacking an ACR-23/MPTL-1 homolog, was tolerant. Monepantel shows an excellent tolerability in mammals and it is also active against multidrug-resistant parasites, indicating that its molecular target is absent or inaccessible in the host and is different from those of the classic anthelmintics. Safety pharmacological studies in rats indicate that MOP does not exert negative effects at a dose of 2000 mg/kg. Unfortunately, recent studies from New Zealand and Australia have reported that the efficacy of this new anthelmintic has declined markedly. Lack of efficacy of MOP was confirmed in the slaughtered sheep in which burdens of T. circumcincta and T. colubriformis showed no significant reductions. Whilst these two parasites now appear solidly resistant, the status of O. venulosum remains less clear.

Phenothiazine, the parent compound of a multitude of present-day drugs, has been employed on an extensive scale for its insecticidal, fungicidal, antibacterial and anthelmintic properties. Phenothiazine was formerly used as an insecticide and as a drug to treat infections with parasitic worms (antihelminthic) in livestock and people. It was introduced as antihelminthic in livestock in 1940 and is considered, with thiabendazole, to be the first modern antihelminthic. Almost a catholicon, its widespread use in animals and man has led to the uncovering of many adverse reactions encompassing effects on blood elements, neuromuscular problems and photosensitization. Its potential side effects have now limited its use. The chemical structure of phenothiazine provides a most valuable molecular template for the development of agents able to interact with a wide variety of biological processes. Synthetic phenothiazines (with aliphatic, methylpiperazine, piperazine-ethanol, piperazine-ethyl, or piperidine side-chain) and/or phenothiazine-derived agents e.g., thioxanthenes, benzepines, imonostilbenes, tricyclic antidepressants, dimetothiazine, and cyproheptadine have been effective in the treatment of a number of medical conditions with widely different etiology. These include various currently clinically used drugs for their significant antihistamic, antipsychotic, anticholinergic (antiparkinson), antipruritic, and/or antiemetic properties.

Bunamidine is a anti-parasitic drug, which was approved by FDA for the treatment of tapeworms in cats and dogs (Scolaban 400 tablets).