Trabajo presentado en el American College of Veterinary Internal Medicine Forum 2011. Junio 2011. Denver, Colorado. USA.dogs in the worldwide, in which breed. iex. age. diet, some anatomical abnormalities, urinary tract infection, urine pH and some geographical and hereditary features in the populations studied have been implicated as risk factors. The effective long-term management of urolithiasis depends on identification and control of the pathophysiological mechanisms involved, which, in turn, depend on accurate knowledge of the mineral composition of the uroliths. The aim of this study was to determine for first occasion the main epidemiological data of canine urolithiasis in Mexico. This study was developed with 491 dogs with urolithiasis from 25 ofthe 33 states of the country.This work has been partially supported by a project Waltham Foundation and the Consejo Nacional de Ciencia y Tecnología (CONACyT) of México.