Evaluation of the administration of Maropitant as analgesic agent and its effect on ovarian laxity in ovariohysterectomies in dogs and cats.

Abstract

Currently, there is a growing tendency to reduce the use of opioids, aiming to implement opioid-free anesthesia protocols. Maropitant, an antiemetic and NK1-1 receptor antagonist, has been proposed as an alternative due to its demonstrated visceral analgesic effect ant its ability to reduce the need for inhalant anesthetics during surgical procedures. The objective of this study was to compare the intraoperative and postoperative analgesic efficacy of maropitant with that of methadone, as well as to assess its effect on ovarian laxity. In this study, 26 female dogs were randomly assigned to two groups. Both groups received the same dose of dexmedetomidine; however, one group (n=13) was premedicated with methadone and the other (n=13) with maropitant. Data collection was performed at three predefined time points: preoperative, intraoperative, and postoperative phases. Physiological parameters, including heart rate, respiratory rate, mean arterial pressure, and end-tidal sevoflurane concentration, were monitored at each time point, along with pain assessments performed during the 4-hour period following extubation. Maropitant resulted in poorer sedation, requiring higher doses of induction agents in these patients. Nevertheless, heart rate (HR) and respiratory rate (RR) values were higher in the maropitant group compared to the methadone group; furthermore, maropitant showed effect that facilitated easier ovarian exteriorization. Maropitant, when used as part of the premedication protocol, was associated with lower postoperative pain scores compared to methadone, particularly during the hours following surgery. Therefore, maropitant may be considered a valuable option when the use of opioids is contraindicated, potentially avoiding the adverse effect associated with this class of drugs.