Acute hyperkalemia as anesthetic complication in a diabetic dog undergoing tumor excision.

A mixed-breed dog with a history of diabetes mellitus underwent surgical removal of multiple colonic adenocarcinomas. The dog acutely developed electrocardiographic changes compatible with hyperkalemia during manipulation of the tumors, which was confirmed and treated. Although it was not possible to confirm clinical tumor lysis syndrome in this dog, the hyperkalemia and resultant arrhythmia that occurred during tumor manipulation were suggestive of acute tumor lysis syndrome. Key clinical message: Hyperkalemia is a serious anesthetic and intraoperative complication that should be considered in dogs undergoing solid tumor resection due to the potential risk of developing acute tumor lysis syndrome. Diabetic patients may also be at increased risk of developing hyperkalemia. Both the potassium concentration and ECG should be routinely monitored during these procedures.