Lesões do sistema urinário em cães

Abstract

This thesis was composed of three scientific papers. The first paper was the more comprehensive. All lesions of the urinary system of dogs necropsied between 1999 and 2010 were analyzed. In this time frame, 3,189 dogs were necropsied at the Laboratório de Patologia Veterinária of the Universidade Federal de Santa Maria (LPV-UFSM) and 1,063 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. Kidneys were 2.8 times more affected than the lower urinary tract (LUT). One third of the lesions in the urinary system were cause of spontaneous death or reason for euthanasia (SD/EUTH) of the affected dogs. The other lesions were considered incidental findings. The main renal lesions diagnosed were: tubulointerstitial nephritis, infarct, granulomatous nephritis, glomerulonephritis, metastatic/multicentric neoplasms, pyelonephritis/pyelitis, and hydronephrosis. The main LUT lesions were: cystitis, presence of viral inclusions bodies, urolithiasis, urinary bladder dilatation, urinary bladder rupture, and metastatic/multicentric neoplasms. Epidemiological aspects such as gender, breed, and age of affected dogs had significant 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. The second paper was focused on urolithiasis. From 1990 to 2010, 4,872 dogs were necropsied at LPV-UFSM. Out of these, 1.5% had uroliths along the urinary tract. The epidemiological profile of the affected dogs showed predominance of males; adults; and pure breeds. Clinical signs suggestive of urolithiasis were informed in 30.3% of the dogs and consisted mainly of hematuria, anuria, dysuria and urinary incontinency. The uroliths were found in one or more anatomical sites, and the main affected ones, in descending order, were urinary bladder, kidney, and urethra. Secondary lesions to urolithiasis were observed in about 40% of the cases. The most prevalent were cystitis, urethral obstruction, hydroureter, hydronephrosis, urinary bladder rupture, and pyelonephritis. In 25% of the affected dogs, SD/EUTH occurred due to the secondary lesions of urolithiasis. Extra-renal lesions of uremia were observed in 9 out of the 76 cases. The third article was focused on urinary system neoplasms of dogs. The main purposes of this study were to establish the prevalence and types of primary and metastatic/multicentric neoplasms of the urinary system in dogs submitted to necropsy in about 21 years at the LPV-UFSM. Neoplasms of the urinary system were present in 113 (2.4%) dogs. Twenty seven were primary neoplasms and 86 were metastatic or part of a multicentric tumor. The majority of the primary neoplasms were of epithelial origin. Thirteen dogs had primary renal neoplasms (prevalence of 0.27% over all dogs necropsied). Cystadenocarcinoma/cystadenoma and renal cell carcinoma were the most prevalent primary renal neoplasms and transitional cell carcinoma was the most prevalent urinary bladder neoplasm. Metastatic or multicentric tumors affecting the urinary system were the most prevalent (76.1%); mesenchymal tumors were more common than epithelial tumors; most of them were localized in the kidney. Metastases of mammary tumors and multicentric lymphoma were the most prevalent histologic types.