Glucagon-like peptide-1 (GLP-1) analogues and inhibitors of its degrading enzyme, dipeptidyl peptidase IV (DPPIV), are interesting therapy options in human diabetics because they increase insulin secretion and reduce postprandial glucagon secretion. Given the similar pathophysiology of human type 2 and feline diabetes mellitus, this study investigated whether the DPPIV inhibitor NVP-DPP728 reduces plasma glucagon levels in cats. Intravenous glucose tolerance tests (ivGTT; 0.5g/kg glucose after 12h fasting) and a meal response test (test meal of 50% of average daily food intake, offered after 24h fasting) were performed in healthy experimental cats. NVP-DPP728 (0.5-2.5mg/kg IV or SC) significantly reduced glucagon output in all tests and increased insulin output in the ivGTT. Follow-up studies will investigate the potential usefulness as therapy in diabetic cats.