Immunoglobulin A and immunoglobulin G biclonal gammopathy in a dog with multiple myeloma.

A nine-year-old golden retriever was referred for evaluation of chronic anorexia, vomiting, and diarrhea. Low body weight, mucous membrane pallor, and palpably enlarged liver and spleen were detected by physical examination. Anemia, hyperglobulinemia, and concurrent trichuriasis and coccidiosis were identified upon initial diagnostic evaluation. Punctate vertebral lysis was apparent radiographically. Atypical plasma cell proliferation was found in the bone marrow, liver, and spleen. An immunoglobulin A and immunoglobulin G biclonal gammopathy was demonstrated by serum protein electrophoresis and immunoelectrophoresis. The dog was diagnosed with multiple myeloma and euthanized per owner request. Multiple myeloma should be considered in the differential diagnosis for biclonal gammopathy in the dog.