Biomaterial Database

Anthelmintic resistance. 1993

T M Craig

Department of Veterinary Pathobiology, Texas A&M University, College Station 77843.

In populations of livestock in which anthelmintics have become the only means of control, individual worms in some species of helminths evade the effects of specific anthelmintics. If these resistant individuals are selected (by removing the susceptible individuals in the population) then the resistant worm population on individual farms becomes dominant in both numbers and effect. This selection of anthelmintic resistant populations is most often reported in equids and small ruminants (the hosts in which anthelmintics are used most frequently). There is little evidence of anthelmintic resistance by Ostertagia in cattle but an understanding of the problem in other grazing species may aid in delaying its onset. Benzimidazole/phenothiazine resistance by small strongyles in horses in widespread. Resistance by various geographic strains of Haemonchus, Teladorsagia and Trichostrongylus against all of the commonly used classes of anthelmintics in small ruminants has been verified. The failure of levamisole to remove adult Ostertagia ostertagi from cattle has been reported in several geographical areas. Resistance is an individual farm problem and each premise has to be evaluated as to which anthelmintics can be used. Drug rotation, especially rapid rotation (less than 1 year) selects for multiple drug resistance. Epidemiologic treatment selects for resistance, but if properly used, requires considerably fewer treatments to prevent disease and the development of resistant populations will be slowed. A combination of strategic and tactical treatments along with evaluation of anthelmintics will be required to enable producers to raise livestock in maximum production units.

UI	MeSH Term	Description	Entries
D007978	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)	L-Tetramisole,Levotetramisole,Decaris,Dekaris,Levamisole Hydrochloride,Solaskil,Hydrochloride, Levamisole
D009349	Nematode Infections	Infections by nematodes, general or unspecified.	Infections, Nematode,Infection, Nematode,Nematode Infection
D010029	Ostertagiasis	A disease of herbivorous mammals, particularly cattle and sheep, caused by stomach worms of the genus OSTERTAGIA.	Ostertagiases
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002418	Cattle Diseases	Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.	Bovine Diseases,Bovine Disease,Cattle Disease,Disease, Bovine,Disease, Cattle,Diseases, Bovine,Diseases, Cattle
D004351	Drug Resistance	Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.	Resistance, Drug
D006376	Helminths	Commonly known as parasitic worms, this group includes the ACANTHOCEPHALA; NEMATODA; and PLATYHELMINTHS. Some authors consider certain species of LEECHES that can become temporarily parasitic as helminths.	Aschelminthes,Gordius,Nematomorpha,Parasitic Worms,Worms, Parasitic,Aschelminthe,Helminth,Nematomorphas,Parasitic Worm,Worm, Parasitic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000829	Animals, Domestic	Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.	Farm Animals,Domestic Animals,Domesticated Animals,Animal, Domestic,Animal, Domesticated,Animal, Farm,Animals, Domesticated,Animals, Farm,Domestic Animal,Domesticated Animal,Farm Animal
D000871	Anthelmintics	Agents that kill parasitic worms. They are used therapeutically in the treatment of HELMINTHIASIS in man and animal.	Anthelmintic,Antihelmintic,Vermifuge,Vermifuges,Antihelmintics