Efficacy of an injectable combination anthelmintic (nitroxynil+clorsulon+ivermectin) against early immature Fasciola hepatica compared to triclabendazole combination flukicides given orally or topically to cattle

The objective was to compare the efficacy against artificially induced 2- and 4-week old early immature triclabendazole-susceptible liver flukes (Fasciola hepatica) of an injectable combination of nitroxynil, clorsulon and ivermectin with oral and pour-on combination formulations containing triclabendazole. Groups of yearling Angus or Angus cross cattle were confirmed fluke free before being artificially infected with 500 Sunny Corner strain triclabendazole-susceptible liver fluke metacercariae. Two or four weeks after infection, cattle were treated with the test combination Nitromec® (10.2mg/kg nitroxynil, 2.0mg/kg clorsulon, 0.2mg/kg ivermectin), or oral Flukazole® C+Se (triclabendazole/oxfendazole/Selenium), oral Fasimec® C (triclabendazole/ivermectin) or Genesis® Ultra Pour-On (triclabendazole/abamectin). At intervals cattle were weighed, faecal sampled for liver fluke egg counts and blood sampled for liver serum enzyme analysis. Cattle were slaughtered 14 weeks after infection for recovery of adult flukes; fluke egg counts and liver pathology assessment. All cattle increased in body weight by 0.4–0.8kg/day but there were no significant differences between control and treated groups or between the treatment groups. Geometric mean 14-week fluke egg counts and total fluke counts for all treatments, were significantly less (p