Renal Subcapsular Abscess Associated with Pyometra in a Dog

A 12-year-old intact female Pomeranian dog was presented with vulvar discharge, lethargy, polyuria, and polydipsia. A complete blood count revealed leukocytosis and anemia. The serum biochemical analyses showed elevated serum alkaline phosphatase activity and blood urea nitrogen. Survey abdominal radiography revealed an enlarged left kidney. Abdominal ultrasonography identified multiple rounded hypoechoic subcapsular lesions in the left kidney. The bilateral uterine horn was enlarged, and contained echogenic fluid. Percutaneous ultrasonographic-guided aspiration of the renal subcapsular lesions was performed on the left kidney. Cytological examination revealed bacterial cocci, degenerated neutrophils, and suppurative inflammation. Bacterial culture produced growth of Escherchia coli. Left nephrectomy and ovariohysterectomy were performed. Dilated uterine fluid was also evaluated for bacterial culture, and showed growth of E. coli. Urine was examined by bacterial culture, and showed negative results. The treatment consisted of antibiotic therapy according to the antibiotic sensitivity test. Based on these findings, the diagnosis was renal subcapsular abscess associated with pyometra. This study suggests that pyometra should be considered as the cause of renal abscess.