Two year-old female miniature schnauzer was presented with depression, abdominal pain and inappetence. Physical examination revealed tachypnea, fever, and abdominal pain. Leukocytosis with neutrophilia was shown in complete blood count. Radiograph revealed the increase of opacity in parallel to vertebra and dislocation of descending colon. Calculi and sludge in bladder, hydronephrosis and dilation of proximal ureter in right kidney were observed in ultrasonographic examination; also, irregular shape of structure in retroperitoneal cavity was observed. Urinalysis showed protein urine and hemtauria. Many epithelial cells, spindle cells, calcium oxalate dihydrate crystals, struvite crystals, amorphous crystals and granular casts, WBC, cocci were examined in urine sediment test. ERD-kit test result was highly positive. Based on those test and excretory urogram pyelonephritis and complete unilateral obstruction of ureter were confirmed. A balloon type structure in retroperitoneal cavity was found through the exploratory laparotomy. In cytologic examination of aspirated fluid from dilated area many degenerated neutrophils and phagocytized cocci were observed. Staphylococcus intermedius was cultured from aspirated fluid. Based on these clinical results retroperitoneal abscesses caused by Staphylococcus intermedius was diagnosed with ureter obstruction and concurrent cystic calculi. Nephrectomy of right kidney with ureter was performed.