Retroperitoneal Suppurative Fistula Caused by Remnant Suture Material in a Poodle Dog

An eight-year-old, 3.4 kg, spayed female poodle dog was referred to Gyeongsang National University Animal Medical Center with obstinate bilateral retroperitoneal subcutaneous abscess. The medical history revealed ovariohysterectomy (OHE), lipoma, and mammary gland tumor excision performed two years ago. The dog presented with left retroperitoneal subcutaneous abscess discharge five months back and was treated by abscess drainage and antibiotics in a local veterinary hospital, but a relapse was reported on discontinuing antibiotics. On physical examination, the dog was febrile (40℃) and both retroperitoneal masses showed typical inflammatory reaction and purulent discharge. On serum chemistry analysis, hyperproteinemia, hyperglobulinemia, and elevated levels of C-reactive protein were observed. Cytologic examination showed degenerative neutrophils and phagocytic macrophages. Radiological examination revealed encapsulated hypoechoic subcutaneous masses in bilateral abdominal flank and the left flank mass was connected with the caudal pole of left kidney through fistula. Based on the diagnostic examination, exploratory celiotomy was recommended and left nephrectomy, and resection of bilateral masses were performed. During procedure, fistula between caudal pole of left kidney and left subcutaneous abscess was detected and suture material was identified. Resected tissue was histologically examined and diagnosed as suppurative abscess caused by the suture material. This case report describes chronic suppurative foreign body reaction including caudal pole of left kidney and bilateral retroperitoneal subcutaneous masses induced by the suture material used in OHE two years ago and the necessity of computed tomography examination to identify character of mass and extent of surgical resection.