Spatial and temporal clustering and risk factors for calcium oxalate compared to struvite uroliths in dogs
This thesis is an investigation of Ontario canine magnesium ammonium phosphate (struvite) and calcium oxalate (CaOx) urolith cases documented by the Canadian Veterinary Urolith Center urolith registry from 1998-2006. The data were evaluated with the spatial scan statistic and found to have statistically significant spatial, temporal and space-time clusters. Variables related to human population density and socioeconomic status were the most likely explanations for the spatial differences between the two cluster types. The results of a multilevel multivariable logistic model suggested that most of the variance in risk of submitting CaOx relative to struvite was explained by individual level factors including diet and demographic variables. In addition, community level or contextual factors such as community wealth and residing in the densely populated area of Toronto also affected the submission patterns. There was evidence of temporal clustering of CaOx relative to struvite uroliths, but a linear trend over time was absent.