Anthelmintic resistance of Ostertagia ostertagi and Cooperia oncophora to macrocyclic lactones in cattle from the western United States

Modelling the consequences of targeted selective treatment strategies on performance and emergence of anthelmintic resistance amongst grazing calves

“…With the emergence of anthelmintic resistance in GI parasites of cattle (Edmonds et al., 2010, Sutherland and Leathwick, 2011, O'Shaughnessy et al., 2014b, Rose et al., 2015) there have been attempts towards developing TST strategies for cattle. This is important, as although resistance has been slow to develop amongst cattle parasites, it appears that multi-drug resistance for multiple parasite species is developing more rapidly than expected (Sutherland and Leathwick, 2011).…”

“…However, in recent years it has become evident that this is also an emerging problem for cattle (Edmonds et al., 2010, Sutherland and Leathwick, 2011, O'Shaughnessy et al., 2014b, Rose et al., 2015). With nematode resistance now present to all three of the broad spectrum anthelmintic classes (benzimidazoles, levamisole and macrocyclic lactones) used on cattle (Sutherland and Leathwick, 2011), control strategies aiming to sustain effective parasitic control are of key importance.…”

Limited efficacy of pour-on anthelmintic treatment of cattle under Swedish field conditions

“…AR in trichostrongyloid cattle nematodes detected by FECRT appears against all major anthelmintic classes, both against ML and to a lesser extent also to benzimidazoles (BZ), particularly on the southern hemisphere (Mejia et al, 2003; Waghorn et al, 2006; Soutello et al, 2007; Suarez and Cristel, 2007; Almeida et al, 2013). However, ML-resistant C. oncophora has also been reported from the United States (US) (Edmonds et al, 2010), the United Kingdom (UK) (Stafford and Coles, 1999; Coles et al, 2001; Sargison et al, 2009, 2010; Orpin, 2010; Stafford et al, 2010; McArthur et al, 2011), and Belgium, Germany and Sweden (Demeler et al, 2009; El-Abdellati et al, 2010b). The reason for AR development has not been fully investigated, but the way in which anthelmintics are used in cattle is believed to be the main cause ( op.…”

Efficacy of major anthelmintics for reduction of fecal shedding of strongyle-type eggs in horses in the Mid-Atlantic region of the United States

“…There is great concern that the development of avermectin/milbemycin (AM) resistance could evolve into the current situation affecting small ruminants with a high prevalence of avermectinresistant Haemonchus contortus in sheep and goats worldwide, as well as AM-resistant parasites in cattle (Fleming et al, 2006;Howell et al, 2008;Edmonds et al, 2010).…”