An abdominal eumycotic mycetoma with multiorgan dissemination was diagnosed in a 2-year-old dog. Clinical signs included fever, vomiting, diarrhea, weight loss, and a palpable abdominal mass. The dog developed disseminated intravascular coagulation and died. Pseudallescheria boydii was isolated from the abdominal mass, liver, and peritoneal fluid. Relevant history included an ovariohysterectomy when the dog was 6 months old, which was complicated by dehiscence of the incision site and evisceration. It appears that P boydii has a propensity for establishing itself in the abdominal cavity of the dog, subsequent to surgical dehiscence.