Canadian veterinarians asked to participate in national disease surveillance of neosporosis, Johne's disease, bovine leukosis, and bovine viral diarrhea

Dear Sir:

The Canadian Food Inspection Agency (CFIA) invites veterinarians to participate as critical players in a National Beef Cow-Calf Survey Project this fall. The project complements previous dairy studies for 4 endemic diseases of concern, referred to as “production limiting diseases” (PLD); namely, neosporosis, Johne's disease, enzootic bovine leukosis (EBL), and bovine viral diarrhea (BVD). It will be the first national assessment of the prevalence of any of these diseases in beef herds across Canada since EBL was studied in 1978.

Large animal veterinarians will be asked to collect blood samples from local beef cow-calf herds. Randomly selected producers will receive a questionnaire in the mail inviting their participation and asking them to name their veterinarian. Participating producers will be required to provide management parameters and, then, to arrange a herd health visit with their veterinarian to collect the samples at fall round-up time. The study involves testing 30 mature cows (> 2 y old) and 10 calves from each herd. The test results will be confidential and reported to the producer. The “veterinarian in practice” (VIP) is critical to the success of this national effort.

The PLD Committee (PLDC) was established in 1997 with support from more than 2 dozen organizations within industry, provincial Departments of Agriculture, and the CFIA. Its 4 targeted diseases are subclinical diseases that resist treatment. Little is known about the level of these diseases in Canadian herds or the management risk factors that contribute to their persistence on beef farms. It is known that healthy looking animals are carriers and spread infection throughout the herd, reducing productivity through abortion, immunosuppression, diarrhea, and lack of thriftiness.

Drs. John Campbell and Cheryl Waldner, veterinary epidemiologists at the Western College of Veterinary Medicine (WCVM), have designed a producer management questionnaire to accompany the serological data. Drs. John Kellar and Christine Power, veterinary epidemiologists with CFIA's Animal Disease Surveillance Unit, have been involved in the project for many years under the aegis of the Canadian Animal Health Network (CAHNet) (1). The study group of animals will include 60 herds in each of British Columbia, Alberta, Saskatchewan, and Ontario, and 100 herds in the Atlantic provinces: Prince Edward Island, Nova Scotia, and New Brunswick are being asked for 30 herds each, while Newfoundland is being asked for 10. Quebec and Manitoba have already completed their collections.

This scientific survey will determine the prevalence of disease at the herd level. Armed with this information, researchers at the WCVM will evaluate management risk factors and develop preventive measures specifically for beef herds, working towards a Canadian Cattle Health Assurance Program. Updates on the project and findings gained from this study will be reported on a regular basis at both the provincial and the national level.

If called upon, please join in this effort, to determine valid prevalence estimates of these infectious diseases in Canadian beef cattle at the herd level.