Pheochromocytomas, tumors of the chromaffin cells of the adrenal medulla, often present with vague clinical signs and are considered diagnostic challenges. The difficulty in developing a presumptive diagnosis stems from the episodic nature of the disease and often unrewarding blood work and radiographic imaging. Fortunately ultrasound, an increasingly common imaging modality, can often localize the lesion to the adrenal glands thus narrowing down the list of possible differential diagnoses. Once a presumptive diagnosis based on a high index of suspicion is made, surgical removal of the mass is the treatment of choice. Unfortunately, pheochromocytomas tend to be highly vascular and may invade local vessels making their excision highly difficult with many intraoperative and post-operative complications. Managing hypertension preoperatively, however, has been shown to significantly decrease short-term mortality postoperatively thus improving prognosis in canines affected with this tumor. This case study details the pathogenesis of pheochromocytomas, relevant anatomy, treatment options, and prognostic indicators.