Behavioral and cardiopulmonary effects of dexmedetomidine-midazolam and dexmedetomidine-midazolam-butorphanol in the silver fox (Vulpes vulpes).

OBJECTIVE

To evaluate the behavior and some cardiopulmonary variables of dexmedetomidine-midazolam or dexmedetomidine-midazolam-butor-phanol in the silver fox (Vulpes vulpes).

STUDY

DESIGN

Blinded, randomized design.

ANIMALS: Sixteen adult silver foxes, aged 7-9 months, weighting 6.0-9.2 kg.

METHODS

Animals were randomly assigned to dexmedetomidine (50 μg kg-1) and midazolam (0.45 mg kg-1) (group DM) or to dexmedetomidine (30 μg kg-1), midazolam (0.45 mg kg-1) and butorphanol (0.25 mg kg-1) (group DMB), administered intramuscularly. Pulse rate (PR), respiratory rate (fR), noninvasive arterial pressures, oxygen saturation (SpO2), rectal temperature (T) and behavioral scores (posture, sedation, antinociception, jaw relaxation and auditory response) were measured at 5, 10, 20, 30, 40, 50 and 60 minutes after injection. Time from drug injection to recumbency with no response to stimuli (IT) and time from administration of atipamezole (0.2 mg kg-1) to standing with coordination (RT) were recorded. The occurrences of adverse events were recorded. Data were analyzed by two-tailed unpaired t-tests and Bonferroni post hoc tests. Significant differences were accepted at p<0.05.

RESULTS

There were no statistically significant differences between the groups for IT or RT. Arterial pressures were higher in DMB at each time point except at 5 minutes. PR was lower in DM at each time point except at 10 and 60 minutes. No significant difference was found between the groups for fR, SpO2 and T. The behavioral scores were significantly lower (lower quality immobilization) in DMB at 5,10 and 60 minutes.

CONCLUSIONS AND CLINICAL RELEVANCE: IT and RT were not different between the groups. Both protocols provided immobilization for 30-40 minutes with excellent muscle relaxation and analgesia adequate for clinical examinations and some simple surgical procedures.