Background & Aim: Spirulina microalgae is known to has beneficial effects in the treatment of many animals diseases. Effects of Spirulina platensis microalgae, singly or in comparison with levamisole drug are not still studied in dogs. Thus, the present study was conducted to investigate the effects of this microalgae on hematological and immunological parameters in dogs.Experimental: In this research, 24 native breed dogs were used for 30 days. The dogs were divided into three groups of eight randomly, including a control group, treatment group (received 2 g Spirulina orally) and the third group received 5 mg/kg Levamisole. At the end of mentioned period, hematocrit percent, Hb, RBC, WBC, Neutrophil, Lymphocyte, Eosinophil, monocyte, basophil levels and immunological factors including IgM, total protein and phagocytic precent were measured.Results: Hematocrit in levamisole receiving group increased significantly (P<0.05). Results showed that RBC and Hb levels in Spirulina receiving group were significantly higher than the control and levamisole groups. Alb and Neutrophil levels in Spirulina receiving group were lower than the other two groups. In addition, Eosinophil and WBC levels in control group were significantly lower than the other two groups, but monocyte and Lymphocyte levels in control group increased significantly (P<0.001). Also, on the 30th day, total protein and phagocytic percent in Spirulina receiving group were significantly higher than others groups. In addition, in Spirulina and levamisole groups a significant increase in IgM level was observed (P<0.001).Recommended applications/industries: It can be concluded that the use of Spirulina in dogs for a short time could improve hematological and immunological factors and the effects of Spirulina alga in the most factors is comparable to levamisole drug. پرونده مقاله