COMPARISON OF MEDETOMIDINE AND FENTANYL-DROPERIDOL IN DOGS - SEDATION, ANALGESIA, ARTERIAL BLOOD-GASES AND LACTATE LEVELS

Medetomidine and fentanyl-droperidol (Innovar-vet) were assessed over a three hour period in 80 healthy dogs. Following physical examination , electrocardiogram (ECG), arterial blood sample analysis, and dynamom eter pressure threshold (analgesia score), the dogs were randomly assi gned to one of four treatments: Miv - medetomidine (750 mug/M2) admini stered intravenously (IV), Mim - medetomidine (1000 mug/M2) administer ed intramuscularly (IM), Iiv - Innovar - vet IV (0.05 mL/kg) or Iim - Innovar-vet IM (0.1 mL/kg). All assessments were carried out by a sing le individual unaware of the treatment used. Objective assessments inc luded temperature, heart and respiratory rates, analgesia score, arter ial blood gases, acid-base and lactate levels. Subjective evaluation i ncluded degree of sedation, response to various clinical procedures, n oise responsiveness, posture, and the incidence of side effects. Onset and duration of effect were also recorded. The ECG strips were assess ed for arrhythmias. Data was analyzed using a 3-way analysis of varian ce for continuous variables and a Chi-square analysis of frequencies. A p value less-than-or-equal-to 0.05 was considered significant. Medet omidine-treated animals had a decreased respiratory rate, longer durat ion of analgesic effect, increased incidence of bradycardia, vomiting and twitching, were less noise responsive and shivered less throughout the study. An increased incidence of second degree heart block with M iv (15 min), a delayed onset and recovery with Mim and increased lacta te levels following Iiv (15 min) were observed. No differences were fo und in other measurements and good to excellent chemical restraint was produced with all treatments in 65% or more cases.