Cardiopulmonary effects of intravenous xylazine, ketamine, and atropine in the dog.

Atropine (0.04 mg/kg of body weight) and the combination of xylazine (1.1 mg/kg) and ketamine (11 mg/kg) were administered IV to dogs, and cardiopulmonary variables were measured. The drug combination caused hypoventilation, as reflected by increased PaCO2 and a 30% decrease in cardiac index, whereas arterial pressure, left atrial pressure, and peripheral resistance were increased. These variables began returning toward base-line values during anesthesia and were not different from base-line values by 30 minutes.