Dogs received intra-articular injections of saline solution ( @ mL/kg -LSB- @ mL/lb -RSB- ) , morphine ( @ mg/kg -LSB- @ mg/lb -RSB- ) , dexmedetomidine ( @ g/kg -LSB- @ g/lb -RSB- ) , or a combination of morphine ( @ mg/kg ) and dexmedetomidine ( @ g/kg ) .