Lesões do sistema urinário em 1.063 cães

The aim of this study was to determine the prevalence, epidemiology, clinical significance, and possible associated causes of the urinary system lesions in dogs necropsied between January 1999 and December 2010 at the Laboratorio de Patologia Veterinaria of the Universidade Federal de Santa Maria (LPV-UFSM). To accomplish this, the necropsy reports were analyzed retrospectively. In this time frame, 3,189 dogs were necropsied and about 30% had lesions in the urinary system. In most of the dogs (79.1%), lesions were single and in about 21% they were multiple, totalizing 1,373 lesions. Out of them, 1,014 (73.8%) were observed in the kidney and 359 (26.2%) were in the lower urinary tract (LUT). One third of the lesions in the urinary system were causes of spontaneous death or reason for euthanasia (SD/EUTH) of the affected dogs. The other two third of the lesions were considered incidental findings. The main renal lesions diagnosed, in descending order of prevalence, were: tubulointerstitial nephritis, infarct, granulomatous nephritis (parasitary), glomerulonephritis, metastatic/multicentric neoplasms, pyelonephritis/pyelitis, and hydronephrosis. The main LUT lesions, in descending order of prevalence, were: cystitis, presence of viral inclusions bodies (morbillivirus), urolithiasis, urinary bladder dilatation, urinary bladder rupture (with uroperitoneum), and metastatic/multicentric neoplasms. Epidemiological aspects such as gender, breed, and age of affected dogs had expressive variations according to the type of lesion diagnosed. Uremia was observed in a significant number of cases of SD/EUTH and was mostly due to renal lesions.