The comparison of clinical and cardiopulmonary effects of xylazine, medetomidine and detomidine in dogs

This study intended to evaluate the effects of alpha(2)-adrenoceptor agonists (xylazine, medetomidine and detomidine) on clinical status and cardiopulmonary system in dogs. A total of 30 dogs were randomly assigned to 3 different groups. Following fasting period of 12 hours, xylazine (1 mg/kg IM), medetomidine (25 mu/kg IM) and detomidine (20 mu g/kg IM) were administered to groups I, II and III, respectively. Body temperature, heart rates, and respiratory rates were recorded at predetermined times before and after injections. Serum electrolyte, biochemical parameters, blood gases were also evaluated in the blood samples before and after injection. ECG was recorded before, during and after sedation. Decrease in heart rate was found significant in all of the groups. Decrease in the respiration rate was statistically significant (P<0.001) for groups I and II, but not for group III. The decrease in body temperature was statistically significant (P<0.01) only in medetomidine group. Regarding to the biochemical parameters, the increase in blood glucose level was only statistically significant (P<0.05) in group I. Bradycardia, sinoatrial block, 2(0) Mobitz Type I, and 2(0) Mobitz Type II block were observed in all groups according to the ECG. Only in medetomidine group, heart rhythm disorders such as escape beat and escape rhythm were observed.