Pain deteriorates the quality of life, induces behavioral abnormalities, and increases morbidity and mortality in animals, including cats. At present, there are limited therapeutic choices, as well as limited knowledge on how to treat visceral pain in cats. Available analgesics often have detrimental effects. Maropitant is a newly developed drug shown to be effective in treating vomiting in cats by blocking certain receptors (NK-1) in the central nervous system. These receptors are also involved in pain pathways. The study will investigate the use of maropitant to promote analgesia in cats. This study will test the analgesic effect of maropitant in cats during spay surgeries. Maropitant should decrease the anesthetic requirements, suggesting an analgesic effect. Maropitant is an important anti-nausea drug in cats but has the potential to also become an important analgesic drug without side effects. This will be the first study addressing the potential use of maropitant to manage painful diseases or procedures such as pancreatitis, chronic gastrointestinal disease, renal failure, and abdominal surgeries, including spays.