Lymphoma is the most common hematopoetic tumor in dogs and the third most common encountered malignancy in routine clinical settings. The most common cause of hypercalcemia in dogs is humeral hypercalcemia of malignancy due to lymphoma. Humeral hypercalcemia of malignancy results in a severe loss of quality of life and failure to control it is a common reason for euthanasia. Hypercalcemia leads to multiple organ failure including renal, gastrointestinal, neuromuscular, and cardiovascular. Treatments are broken into acute care and chronic management. The clinical signs and treatments for this condition will be detailed in this paper.