Cardiopulmonary effects of intramuscular xylazine-ketamine in calves.

The cardiopulmonary effects of an intramuscular xylazine (0.088 mg/kg)-ketamine (4.4 mg/kg) drug combination were evaluated in calves. Heart rate, central venous and mean pulmonary artery blood pressures, and cardiac output did not change after drug administration. Mean arterial blood pressure decreased significantly (P less than 0.05) 15 minutes after drug administration. Respiratory frequency increased significantly (P less than 0.05) whereas arterial partial pressure of oxygen (PaO2) decreased significantly (P less than 0.05) after drug administration. The duration of lateral recumbency was 55.7 +/- 10.4 minutes. Immediate or long-term adverse effects were not observed.