Evaluation of the antiemetic efficacy of maropitant in dogs medicated with morphine and acepromazine

Abstract

Objective: To evaluate whether maropitant (1 mg kg(-1)) injected subcutaneously (SC), administered simultaneously or 30 minutes prior to intramuscular (IM) administration of morphine (0.5 mg kg(-1)) and acepromazine (0.05 mg kg(-1)), reduces the incidence of salivation, retching and emesis in dogs.

Study design: Randomized, controlled, prospective clinical trial.

Animals: Sixty dogs scheduled for an ovariohysterectomy as part of a population control program.

Methods: Dogs were randomly allocated to be administered maropitant (1 mg kg(-1)) SC simultaneously (group M0) or 30 minutes prior to (group M30) administration of morphine (0.5 mg kg(-1)) and acepromazine (0.05 mg kg(-1)) IM. A control group was administered normal saline (C) at T-30 and T0. Dogs were observed for 30 minutes after morphine-acepromazine administration. The occurrence of vomiting, retching and salivation were recorded, as well as the time to first emesis and the number of emetic events per dog.

Results: The occurrence of salivation was not different between the groups. Retching and vomiting occurred significantly less frequently in M30 than in the other two groups (p < 0.02). The number of emetic events was also significantly less for M30 than for the other two groups (p = 0.01). When emesis occurred, the time to the first emetic event was similar among the groups.

Conclusions and clinical relevance: Maropitant (1 mg kg(-1)) SC reduced the frequency of morphine-induced emesis by as much as 70% when administered 30 minutes in advance. Simultaneous administration of maropitant and morphine-acepromazine produced no measurable effect on the frequency of retching or vomiting.

Keywords: acepromazine; dogs; maropitant; morphine; vomiting.