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 Unpublished) | 71.2 |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 Unpublished) | 2.0 |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 Unpublished) | 48 |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%