Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/12/1996
Publication Date: N/A
Technical Abstract: Winter dysentery (WD) is a disease of cattle characterized by diarrhea suddenly affecting many adults in a herd. The disease occurs worldwide in dairy and beef animals. Bovine coronavirus (BCV) has been recovered from the feces of affected animals and rising BCV antibody titers have been demonstrated in affected herds. However, few controlled studies have been conducted to fully investigate the role of BCV, or other risk factors, in WD outbreaks. We conducted a case-control study during a two-year period to test the association of herd exposure to BCV with the occurrence of WD, as well as to explore the role of herd exposures to bovine viral diarrhea virus (BVDV), Salmonella spp., Cryptosporidium spp., and various management factors in the WD syndrome. Twelve case herds and 24 control herds were investigated. Four herd-level exposures were identified as potentially being associated with the occurrence of WD based on multivariate logistic regression analysis: 1) increasing herd prevalence of adult cows showing a 4-fold or greater rise in BCV IgG antibody ELISA seroresponse (odds ratio = 58.8 for every 10% increase in herd prevalence, p less than 0.0001; 2) increasing herd prevalence of adult cows showing a greater than or equal to 4-fold BVDV neutralizing antibody seroresponse (odds ratio = 3.4 for every 10% increase in herd prevalence, p=0.0534); 3) housing cattle in comfort stalls or stanchion barns rather than freestalls (odds ratio=23.7, p=0.0680); and 4) the use of manure handling equipment to mix or deliver feed (odds ratio=15.7, p=0.0917). Our findings suggest that herd-level BCV exposure is associated with many WD outbreaks, that some WD outbreaks may be associated with acute BVD infection, and that certain management practices may increase the risk of WD outbreaks.