title: Efficacy of treatment of cattle for liver fluke at housing: influence of differences in flukicidal activity against juvenile Fasciola hepatica.
abstract: Flukicides are commonly administered at housing to cattle that have grazed fluke-infected pastures or that have been purchased from endemic areas. The choice of product is determined by numerous factors, one of which is the stages of Fasciola hepatica that are killed. Flukicides can be categorised into three main groups: (A) those that kill all juvenile stages and adults; (B) those that kill juveniles from six to eight weeks of age and adults and (C) those that kill adults only. This study was conducted on a commercial beef farm in Scotland and was designed to compare the efficacy of flukicides from each of these three classes in terms of their effects on faecal egg output, coproantigen and liveweight gain. The majority of animals in the untreated control group were positive for coproantigen, fluke eggs or both throughout the study duration of 16 weeks. Egg reappearance interval following housing treatment was eight weeks for clorsulon and 13 weeks for nitroxynil, though patent infections in both groups developed in only a small minority of animals; no fluke eggs were recovered from cattle treated with triclabendazole. Coproantigen was detected four weeks before the reappearance of fluke eggs in the dung. Animals treated with flukicides had significantly fewer faecal samples positive for eggs (P<0.006) and coproantigen (P<0.05) following treatment compared with the controls. Despite differences in the efficacy profiles among the flukicide-treated groups, there were no significant differences (P>0.05) in growth rates among any of the four treatment groups. There was, however, a significant negative association (P<0.001) between fluke positivity at housing and subsequent growth performance, irrespective of treatment group.
authors.affiliation: Scottish Centre for Production Animal Health and Food Safety, School of Veterinary Medicine, University of Glasgow, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: A B
authors.initials: AB
authors.lastname: Forbes
authors.affiliation: Moredun Scientific, Pentlands Science Park, Bush Loan, Penicuik, Midlothian EH26 0PZ, UK.
authors.forename: D
authors.initials: D
authors.lastname: Reddick
authors.affiliation: Veterinary Genes and Proteins Group, Institute of Biodiversity, Animal Health and Comparative Medicine, Garscube Campus, Glasgow University, Bearsden Road, Glasgow G61 1QH, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Stear
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology / Q000627:therapeutic use*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy*; D005210:Fasciola hepatica / Q000187:drug effects* / Q000254:growth & development; D005211:Fascioliasis / Q000188:drug therapy / Q000662:veterinary*; D005243:Feces / Q000469:parasitology; D006799:Housing, Animal; D010270:Parasite Egg Count / Q000662:veterinary; D016896:Treatment Outcome
chemical_list: D000871:Anthelmintics
keywords: Anthelmintics; Cattle; Fasciolosis