Spontaneous nephro-cutaneous fistula with pyonephrosis in two dogs: two case reports

This report describes the case of spontaneous nephro-cutaneous fistula with pyonephrosis due to renal calculi and obstructive nephropathy without renal surgery or trauma history in two dogs. A five-year-old, female, Shih-tzu and a seven-year-old, female, Maltese were presented with erythematous swelling, and subcutaneous abscess formation in their flanks. Complementary exams were performed and ultrasonography revealed marked enlargement of the kidneys with hyperechoic purulent debris filling, subcutaneous abscesses and the formation of draining sinus tracts between renal abscesses and subcutaneous tissue. At surgery, kidneys were grossly dilated and contained purulent material, which was visible in the draining sinus tract in the abdominal wall. Thus, a nephrectomy was performed. The dogs recovered uneventfully and three months later there were no further specific problems.