Evaluation of maropitant's analgesic and tissue relaxation effects during ovariohysterectomy in bitches.

This prospective, randomized, blinded clinical study aimed to compare the intraoperative and postoperative analgesic effects of maropitant versus methadone in female dogs undergoing elective ovariohysterectomy and to evaluate whether maropitant facilitates ovarian ligament exteriorization, potentially through modulation of visceral tone. Seventy-two healthy bitches were randomly assigned to receive dexmedetomidine with either methadone (Group M, n = 34) or maropitant (Group MAR, n = 38). In addition to assessing intraoperative cardiorespiratory parameters and anesthetic requirements, postoperative pain was evaluated using the CMPS-SF scale. Exteriorization of the ovaries was scored by the surgeon. Maropitant-treated dogs showed higher HR and RR during ovarian traction, easier ovary exteriorization, lower postoperative pain scores at 0, 1, and 2 h, and reduced need for rescue analgesia. These findings suggest that maropitant provides effective analgesia and may modulate visceral tone, facilitating surgical manipulation and enhancing patient comfort.