Cyclosporine and prednisone are immunosuppressive drugs that are commonly used in combination for the treatment of immune-mediated diseases, and have been shown to individually cause significant suppression of IL-2. Currently, no studies have been performed to determine how a combination of the two drugs would impact suppression of IL-2, and if an additive or synergistic effect on cytokine production could be demonstrated, as in studies of other species. An additive effect of immunosuppression associated with this drug combination could allow clinicians to decrease dosages of drugs, thereby reducing drug costs and minimizing adverse drug side effects. In a cross-over study design using six healthy dogs, the expression of IL-2 was affected with administration of cyclosporine, prednisone, or a combination of each drug. However, there was no significant difference in the level of immunosuppression compared to cyclosporine alone. Small sample size and the dosages of each drug used potentially affected the strength of the results.