title: Neospora caninum is the leading cause of bovine fetal loss in British Columbia, Canada.
abstract: The protozoan pathogen Neospora caninum is recognized as a leading cause of infectious abortions in cattle worldwide. To evaluate the impact of neosporosis on dairy and beef herd production, a retrospective, longitudinal study was performed to identify the impact of neosporosis alongside other causes of fetal abortion in British Columbia, Canada. Retrospective analysis of pathology records of bovine fetal submissions submitted to the Animal Health Centre, Abbotsford, British Columbia, a provincial veterinary diagnostic laboratory, from January 2007 to July 2013 identified 182 abortion cases (passive surveillance). From July 2013 to May 2014, an active surveillance program identified a further 54 abortion cases from dairy farmers in the Upper Fraser Valley, British Columbia. Of the total 236 fetal submissions analyzed, N. caninum was diagnosed in 18.2% of cases, making it the most commonly identified infectious agent associated with fetal loss. During active surveillance, N. caninum was associated with 41% of fetuses submitted compared to 13.3% during passive surveillance (p<0.001). Breed of dam was significantly associated with N. caninum diagnosis, with a higher prevalence in dairy versus beef breeds, and fetuses of 3-6 months gestational age had the highest prevalence of N. caninum. There was no significant association with dam parity. N. caninum was diagnosed in every year except 2009 and cases were geographically widespread throughout the province. Furthermore, the active surveillance program demonstrates that N. caninum is highly prevalent in the Upper Fraser Valley and is a major causal agent of production losses in this dairy intensive region.
authors.affiliation: Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada; The Animal Health Center, BC Ministry of Agriculture, 1767 Angus Campbell Road, Abbotsford, British Columbia V3G 2M3, Canada.
authors.forename: Devon J
authors.initials: DJ
authors.lastname: Wilson
authors.affiliation: Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
authors.forename: Karin
authors.initials: K
authors.lastname: Orsel
authors.affiliation: Greenbelt Veterinary Services Ltd., 8451 Harvard Place, Chilliwack, British Columbia V2P 7Z5, Canada.
authors.forename: Josh
authors.initials: J
authors.lastname: Waddington
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Malavika
authors.initials: M
authors.lastname: Rajeev
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Amy R
authors.initials: AR
authors.lastname: Sweeny
authors.affiliation: The Animal Health Center, BC Ministry of Agriculture, 1767 Angus Campbell Road, Abbotsford, British Columbia V3G 2M3, Canada.
authors.forename: Tomy
authors.initials: T
authors.lastname: Joseph
authors.affiliation: Molecular Parasitology Section, Laboratory of Parasitic Diseases, NIAID, National Institutes of Health, Bethesda, MD, USA. Electronic address: griggm@niaid.nih.gov.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Grigg
authors.affiliation: The Animal Health Center, BC Ministry of Agriculture, 1767 Angus Campbell Road, Abbotsford, British Columbia V3G 2M3, Canada. Electronic address: Stephen.Raverty@gov.bc.ca.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Raverty
mesh_terms: D037881:Aborted Fetus / Q000469:parasitology; D000034:Abortion, Veterinary / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology*; D000367:Age Factors; D000818:Animals; D001947:Breeding; D001955:British Columbia / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000469:parasitology*; D003048:Coccidiosis / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D005260:Female; D008137:Longitudinal Studies; D018688:Neospora / Q000502:physiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Abortion; Bovine neosporosis; British Columbia; Fetal loss; Neospora caninum