Successful treatment of peritoneal nocardiosis caused by Nocardia paucivorans in a dog

Case history A 7-year-old neutered female Labrador Retriever from Hesse (Germany) was referred for evaluation of peritoneal nodular masses identified by the referring veterinarian during an investigation for a 2-month history of lethargy. Clinical findings and treatment Ultrasonographic examination of the abdomen showed multiple cavernous nodules in the intra-abdominal fat and greater omentum surrounded by free fluid. These findings were suspicious of steatitis and fatty tissue necrosis in the cranial abdomen. Cytologic and microbiological analysis of fine-needle aspirates of the fatty tissue and abdominal fluid revealed septic pyogranulomatous inflammation caused by Nocardia paucivorans. The septic abdomen indicated surgical management was appropriate and a celiotomy was performed, which revealed an inflammed mass attached by fibrous tissue to the spleen, stomach and liver. All abnormal tissue including parts of the greater omentum and the spleen, were removed and samples taken for histopathology and microbial culture. Following surgery, the dog was treated with amoxicillin/clavulanic acid. After initially improving, the dog's condition deteriorated 3 months later. Based on ultrasonographic and cytologic findings, and bacterial culture, recurrence of peritoneal nocardiosis was confirmed. In a second celiotomy, multiple inflammatory mass lesions inflammed masses in the remaining greater omentum were removed. After surgery, antimicrobial therapy was changed to trimethoprim/sulfamethoxazole for a 10-month period. No recurrence of clinical signs was reported 6, 12 and 27 months after the initial surgery. Diagnosis Peritonitis caused by Nocardia paucivorans.

Automated summary

This case involved a 7-year-old neutered female Labrador Retriever from Germany with peritoneal nodular masses caused by Nocardia paucivorans. Surgical management and antimicrobial therapy were effective in treating the infection, with no recurrence after 27 months.