title: Evaluation of the analgesic properties of acepromazine maleate, oxymorphone, medetomidine and a combination of acepromazine-oxymorphone.
abstract: OBJECTIVE
  To determine the presence and duration of analgesia after oxymorphone, acepromazine maleate, acepromazine-oxymorphone combination and medetomidine administration in dogs.
  
  
  METHODS
  Blinded, controlled study.
  
  
  METHODS
  Six adult beagle dogs.
  
  
  METHODS
  Each dog participated in five trials receiving acepromazine maleate (0.2 mg kg-1IM), oxymorphone (0.2 mg kg-1IM), acepromazine-oxymorphone drug combination (0.2 mg kg-1each IM), medetomidine (20 μg kg-1IM) and sterile saline (control). Two specially designed instruments were used for analgesia determination: a heat device (HD) utilized a linear ramped intensity incandescent bulb and a pressure device (PD) consisted of a pneumatic cylinder that protruded a 2.5-cm bolt. The minimum pressure and heat necessary to produce an avoidance response were determined. Analgesia testing was performed prior to and at 30-minute intervals for six hours after drug administration.
  
  
  RESULTS
  Oxymorphone, acepromazine-oxymorphone and medetomidine significantly elevated both pressure and heat response thresholds compared to controls and acepromazine. Both medetomidine and acepromazine-oxymorphone provided a significantly longer duration of analgesia than oxymorphone. No adverse effects were observed at any of the thermal or pressure application sites.
  
  
  CONCLUSIONS
  Oxymorphone, medetomidine and acepromazine-oxymorphone produced significant analgesia with medetomidine and acepromazine-oxymorphone providing the longest duration of analgesia.
authors.affiliation: The Ohio State University, Department of Veterinary Clinical Sciences, 601 Vernon L. Tharp St. Columbus, OH 43210, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Barnhart
authors.affiliation: The Ohio State University, Department of Veterinary Clinical Sciences, 601 Vernon L. Tharp St. Columbus, OH 43210, USA.
authors.forename: John A E
authors.initials: JA
authors.lastname: Hubbell
authors.affiliation: The Ohio State University, Department of Veterinary Clinical Sciences, 601 Vernon L. Tharp St. Columbus, OH 43210, USA.
authors.forename: William W
authors.initials: WW
authors.lastname: Muir
keywords: Acepromazine; analgesia; dogs; medetomidine; oxymorphone