The incidence of nephroliths and chronic kidney disease (CKD) appear to be increasing in cats. This study evaluated the potential relationship between CKD and nephroliths. The most appropriate treatment for cats with nephroliths is unclear. Since most of the nephroliths are composed of calcium salts, no medical dissolution methods are available. Surgical removal is associated with high morbidity and mortality and thus may not be the best option in all cases, either. The study followed 14 cats with stage II (mild) or 3 (moderate) kidney disease, 7 of which had nephroliths and were in a separate long-term study evaluating nutritional management of CKD. Three of the case cats and 3 control cats ate a food modified for feline kidney disease, and the other cats ate a maintenance food. All of the cats were evaluated every 3 months for 24 months or until they reached a study end point (uremic crisis or death). There were no clinically important differences in parameters measured during the study period. Cats that had an increase in the size of the nephroliths were fed the maintenance food. No association was detected between nephrolithiasis and rate of disease progression, incidence of uremic crisis, or death. A case-control study of the effects of nephrolithiasis in cats with chronic kidney disease.

Ross SJ, Osborne CA, Lekcharoensuk C, et al. JAVMA 230:1854-1859, 2007.