Triclabendazole (Fasinex™, Flukazole™) Resistance

Since 1983 control of liver fluke infection in dairy cattle has historically relied on the strategic use of flukicides, particularly triclabendazole (Fasinex™, Flukazole™), the only registered product that kills immature and adult liver fluke in dairy cattle. Triclabendazole-resistant (TCBZ-R) liver fluke has been reported in Europe, South America and most recently in 5 of 5 dairy herds in the Macalister and Upper Murray irrigation districts (Table 1).

Table 1. Individual farms on which Triclabendazole resistance in cattle has been reported in VIC and NSW.
Location State Industry Publication % reduction in FEC1
Numbugga NSW Beef (Brockwell et al.2014) 88.4
Gireke NSW Beef (Brockwell et al.2014) 19.9
Tallangatta VIC Beef (Brockwell et al.2014) 78.9
MID VIC Dairy (Brockwell et al.2014) 18.7
MID VIC Dairy (Elliott et al.2015) 0.0
Kergunyah South VIC Dairy (Kelley et al. Unpublished) 71.2
MID VIC Dairy (Kelley et al. Unpublished) 2.0
MID VIC Dairy (Kelley et al. Unpublished) 48

1The APVMA guidelines state that resistance is declared when drug efficacy is <90%