The role of targeted selective treatments in the development of refugia-based approaches to the control of gastrointestinal nematodes of small ruminants

• Published in: Veterinary parasitology Vol. 164; no. 1; pp. 3 - 11
• Main Authors: Kenyon, F., Greer, A.W., Coles, G.C., Cringoli, G., Papadopoulos, E., Cabaret, J., Berrag, B., Varady, M., Van Wyk, J.A., Thomas, E., Vercruysse, J., Jackson, F.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16.09.2009; Amsterdam; New York: Elsevier; Elsevier
• Subjects: anemia (disease); Animal biology; Animals; Anthelmintic resistance; anthelmintics; body weight; Control; digestive system diseases; disease control; drug resistance; Gastrointestinal Diseases - parasitology; Gastrointestinal Diseases - prevention & control; Gastrointestinal Diseases - veterinary; Gastrointestinal nematodes; gastrointestinal system; goat diseases; Goat Diseases - parasitology; Goat Diseases - prevention & control; Goats; Life Sciences; literature reviews; milk yield; nematode infections; Nematode Infections - parasitology; Nematode Infections - prevention & control; Nematode Infections - veterinary; refuge habitats; Refugia; Sheep; sheep diseases; Sheep Diseases - parasitology; Sheep Diseases - prevention & control; Targeted selective treatments; Veterinary medicine and animal Health; Refugia; Control; Gastrointestinal nematodes; Goats; Anthelmintic resistance; Sheep; Targeted selective treatments; anthelmintic resistance; goats; gastrointestinal nematodes; control; refugia; targeted selective treatments; sheep
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2009.04.015

Anthelmintic resistance is recognised as a major problem affecting small ruminant production worldwide and now threatens the sustainability of many of these systems. One method that has been proposed to prolong the efficacy of our current anthelmintics is the maintenance of a parasite population in refugia (unexposed to a drug) which will maintain the genes for susceptibility within the parasite population. Management strategies that employ refugia-based methods include targeted or strategically timed whole flock treatments, targeted selective treatments (TST), whereby only a proportion of the flock is treated at any one time, and the dilution of resistant with susceptible parasites. The ability to effectively target anthelmintic use relies on the identification of those animals that will most benefit from treatment. This review explains the concept of refugia, describes the role of refugia-based approaches to the management of anthelmintic resistance and reviews the markers that have been studied as indicators for TSTs as well as the implementation of refugia-based strategies. Recent results suggest that targeting anthelmintic treatment on the basis of anaemia, milk production and liveweight gain may offer a means of reducing anthelmintic usage whilst still maintaining animal performance.