Dexmedetomidine is a drug commonly used in cats for its calming and pain-relieving effects. It is also sometimes used prior to general anesthesia. However, its use is mostly indicated in relatively young, healthy cats, because it produces severe effects on the cardiovascular system. MK-467 is a drug that is expected to prevent these cardiovascular effects, while preserving the beneficial effects of dexmedetomidine when administered simultaneously. It has been studied in dogs and sheep, but not in cats. This study is a continuation of a previously funded project (W14-015) proposed to determine if MK-467 delivered intramuscularly would offer a clinically attractive solution with limited negative effects in increasing the tolerance of dexmedetomidine in cats.