A 12-year-old female Shih Tzu dog was referred with diarrhea. Hematological examination indicated severe non-regenerative anemia. Bone marrow aspiration smears and core biopsy specimens revealed normal bone marrow. Based on those results, non-regenerative immune-mediated anemia was diagnosed. The dog was initially treated using prednisolone and cyclosporine. However, this treatment regimen did not prove effective. Nevertheless, the patient achieved a good hematological response after the administration of a combination therapy of human immune globulin and mycophenolate mofetil. Such a combination therapy may prove effective against non-regenerative immune-mediated anemia.