Lymphoma of the urinary bladder with concomitant septic peritonitis in a dog

A 6-year-old, female, neutered German shepherd dog presented with an acute history of stranguria and pollakiuria. The dog was depressed but the remainder of the examination was unremarkable. Urine cytology revealed severe bacteriuria and pyuria, suggesting urinary tract infection, and a low number of large atypical lymphoid cells. Abdominal ultrasound revealed the presence of diffuse thickening of the urinary bladder wall in the area of the trigone, enlargement of the left medial iliac lymph node and a large volume of peritoneal effusion. Cytology of the lymph node confirmed large cell lymphoma, and cytology of the abdominal effusion revealed septic neutrophilic inflammation. Urinary bladder lymphoma and septic peritonitis were diagnosed, and euthanasia was elected. Full gross and histopathological postmortem examination concluded the presence of a primary urinary bladder B-cell lymphoma. No definitive cause of the septic peritonitis could be established, but bacterial translocation from the urinary bladder was suspected.