Multiple myeloma and macroglobulinemia are the most common immunoglobulin-producing neoplasms seen in the dog. Treatment with the alkylating agents in combination with prednisone may significantly prolong survival. Supportive management of associated complications is imperative to ensure that the individual case receives optimal care. The use of clinical staging seems to be of value in establishing prognosis; however, response to therapy may be more significant, for many dogs present with advanced disease. In the high-risk patient, one should consider using investigational combination drug protocols which are available at a referral center. Although a "cure" is unlikely, the prospect of the animal having a fairly normal, healthy life for an extended period of time (over a year in the majority of cases) should encourage veterinarians to recommend evaluation for treatment in dogs with multiple myeloma and macroglobulinemia.