Untreated dogs have an average survival time of 60 days.[20] Lymphoma with a histologic high grade generally respond better to treatment but have shorter survival times than dogs with low grade lymphoma.[2] Dogs with B-lymphocyte tumors have a longer survival time than T-lymphocyte tumors.[3] Mediastinal lymphoma has a poorer prognosis than other types, especially those with hypercalcemia.[4] Clinical stage and substage have some prognostic value, with poorer prognosis associated with Stage V disease, and with substage b (clinical illness at time of presentation).[21]