Association between patient-related factors and risk of calcium oxalate and magnesium ammonium phosphate urolithiasis in cats

Objective - To determine whether breed, age, sex, or reproductive status (ie, neutered versus sexually intact) was associated with the apparent increase in prevalence of calcium oxalate (CaOx) uroliths and the decrease in prevalence of magnesium ammonium phosphate (MAP) uroliths in cats over time. Design - Case-control study. Animals - Case cats consisted of cats with CaOx (n = 7,895) or MAP (7,334) uroliths evaluated at the Minnesota Urolith Center between 1981 and 1997. Control cats consisted of cats without urinary tract disease admitted to veterinary teaching hospitals in the United States and Canada during the same period (150,482). Procedure - Univariate and multivariate logistic regression were performed. Results - British Shorthair, Exotic Shorthair, Foreign Shorthair, Havana Brown, Himalayan, Persian, Ragdoll, and Scottish Fold cats had an increased risk of developing CaOx uroliths, as did male cats and neutered cats. Chartreux, domestic shorthair, Foreign Shorthair, Himalayan, Oriental Shorthair, and Ragdoll cats had an increased risk of developing MAP uroliths, as did female cats and neutered cats. Cats with CaOx uroliths were significantly older than cats with MAP uroliths. Conclusions and Clinical Relevance - Results suggest that changes in breed, age, sex, or reproductive status did not contribute to the apparent reciprocal relationship between prevalences of CaOx and MAP uroliths in cats during a 17-year period. However, cats of particular breeds, ages, sex, and reproductive status had an increased risk of developing CaOx and MAP uroliths.