The sedative effects of intramuscular low-dose medetomidine in combination with butorphanol or methadone in dogs.

OBJECTIVE

To compare the sedative effects of an intramuscular (IM) low dose of medetomidine in combination with butorphanol or methadone in dogs.

STUDY

DESIGN

Prospective, blinded, randomized clinical trial.

ANIMALS: Forty-eight healthy adult dogs that required sedation for diagnostic or surgical elective procedures.

METHODS

Dogs were sedated IM with medetomidine (2.5 μg kg(-1)) and either butorphanol (0.4 mg kg(-1)) or methadone (0.4 mg kg(-1)). The degree of sedation was assessed every 10 minutes, for 30 minutes, using a numeric descriptive scale. Data on heart rate (HR), respiratory rate, capillary refill time, temperature and response to a toe pinch were recorded. The response to venous catheterization at minute 30 was also evaluated.

RESULTS

Both combinations produced moderate to deep sedation with a maximal effect at 20-30 minutes without significant differences in the degree of sedation between the treatments at any studied time-point. HR decreased from minute 10 to minute 30 with both opioid combinations (p<0.05); this reduction did not differ between groups (p>0.05). No differences between groups were detected in any of the other variables.

CONCLUSIONS AND CLINICAL RELEVANCE: Combinations of a low dose of medetomidine with butorphanol or methadone, respectively, provide similar degrees of sedation.