title: Treatment against coccidiosis in Norwegian lambs and potential risk factors for development of anticoccidial resistance-a questionnaire-based study.
abstract: The objectives of this study were to investigate the use of anticoccidials in Norwegian sheep flocks and identify farms with management procedures likely to select for drug resistance. Data were obtained by a questionnaire sent to all members of the Norwegian Sheep Recording System in October 2015. The data set consisted of 1215 answers, corresponding to 8.5% of Norwegian sheep flocks. Anticoccidials were used in 82.7% of flocks. Main treatment was at turnout (38.6% of treated flocks) or 1 week after turnout (32.4%). Interestingly, clinical signs possibly related to coccidiosis were observed by almost 40% of the farmers after treatment, which might be an indication of drug resistance. Correlations between the apparently reduced anticoccidial efficacy and management conditions, such as the size of the farms, were found. From the farmers' perspective, metaphylactic treatment was used in 88.5% of treated flocks, of which approximately one third had no history of clinical coccidiosis. Even though farmers seem aware of the importance of good drenching routines based on reliable estimates of weights and calibration of drench guns, drench gun used for anticoccidial administration was never calibrated in 12.1% of the flocks. Finally, dose estimation was made by visual appraisal in 27.5% of the flocks, which can lead to incorrect dosing. Based on the present study, it cannot be determined whether the apparent treatment failure was related to management practises, incorrect administration of the drug, other infections or actual anticoccidial drug resistance.
authors.affiliation: Faculty of Veterinary Medicine, Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Kyrkjevegen 332/334, 4325, Sandnes, Norway. ane.odden@nmbu.no.
authors.forename: Ane
authors.identifier: http://orcid.org/0000-0002-1737-1700
authors.initials: A
authors.lastname: Odden
authors.affiliation: Norwegian Veterinary Institute, Ullevålsveien 68, P.O. Box 750 Sentrum, 0106, Oslo, Norway.
authors.forename: Heidi L
authors.initials: HL
authors.lastname: Enemark
authors.affiliation: Faculty of Veterinary Medicine, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033, Oslo, Norway.
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Robertson
authors.affiliation: Parasitology Unit, Department of Animal Pathology, Faculty of Veterinary Medicine, University of Las Palmas de Gran Canaria, 35416 Arucas, Las Palmas, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruiz
authors.affiliation: Animalia Norwegian Meat and Poultry Research Centre, P.O. Box 396 Økern, 0513, Oslo, Norway.|Faculty of Veterinary Medicine, Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep, 0033, Oslo, Norway.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Hektoen
authors.affiliation: Faculty of Veterinary Medicine, Department of Production Animal Clinical Sciences, Norwegian University of Life Sciences, Kyrkjevegen 332/334, 4325, Sandnes, Norway.
authors.forename: Snorre
authors.initials: S
authors.lastname: Stuen
mesh_terms: D000818:Animals; D003048:Coccidiosis / Q000188:drug therapy / Q000453:epidemiology / Q000662:veterinary*; D004351:Drug Resistance; D009664:Norway / Q000453:epidemiology; D012307:Risk Factors; D012756:Sheep; D012757:Sheep Diseases / Q000188:drug therapy* / Q000453:epidemiology / Q000469:parasitology; D011795:Surveys and Questionnaires
keywords: Anticoccidials; Drug resistance; Eimeria spp.; Norway; Ovine coccidiosis