Tei index of left ventricular (myocardial performance index) has been shown to be clinically useful for estimating left ventricular function, including both systolic and diastolic function. Objective: This study aimed to determine the side effects of xylazine and two narcotics in combination with acepromazine, to evaluate the Tei index in healthy dogs, Methods: thirty dogs otherwise healthy were enrolled in the study randomly allocated into three groups. Group 1 was sedated with Xylazine (2 mg / kg IM), group 2 was sedated with buprenorphine (5μ/Kg IM) and acepromazine (0.05 mg / kg IM) group 3 was fentanyl (5 μ / kg IM) and acepromazine (0.05 mg / kg IM). Results: significant increase in TEI index and a decrease in fractional shortening, Ejection fraction and heart rate in dogs medicated with alpha 2 agonists compared with narcotics in combination with acepromazine, which maintained a good cardiovascular and hemodynamic stability with no statistically significant and side effects. Conclusion, the study showed that narcoleptoanalgesic didn¿t affect the TEI index like Xylacine does.