EPIZOOTIOLOGIC EVALUATION OF UROLITHIASIS IN CATS - 3,498 CASES (1982-1992)

Objective-To test the hypothesis that breed, sex, and age oi cats, and anatomic location of uroliths are risk factors for calcium oxalate an d magnesium ammonium phosphate urolithiasis. Design-Retrospective case -control study. Sample Population-Records of 3,498 feline urolith acce ssions submitted between September 1982 and September 1992. Procedure- Mineral composition of feline uroliths was quantitatively analyzed. Od ds ratios and 95% confidence intervals were calculated for breed, sex, age, and urolith location as risk factors for calcium oxalate and mag nesium ammonium phosphate urolith formation. The population at risk wa s defined as all cats for which that type of urolith had been submitte d. The control population was all cats for which uroliths had been sub mitted, excluding cats with the type of urolith being evaluated. Resul ts-Burmese, Persian, and Himalayan breeds were at higher risk for deve loping calcium oxalate uroliths, but at reduced risk for developing ma gnesium ammonium phosphate uroliths. Compared with females, neutered m ale cats had a higher risk for developing calcium oxalate uroliths, bu t a reduced risk for developing magnesium ammonium phosphate uroliths. The risk for calcium oxalate urolith formation increased with age. On e- to 2-year-old female cats had the highest risk for magnesium ammoni um phosphate uroliths. Uroliths removed from the kidneys were more lik ely to be composed of calcium oxalate than of magnesium ammonium phosp hate. Clinical Implications-Breed, sex, and age of cats, and anatomic location of uroliths should be considered when evaluating risk of calc ium oxalate and magnesium ammonium phosphate urolithiasis in urolith-f orming cats.