Effect of Xylazine, Xylazine/Fentanyl and Xylazine/Nalbuphine on Hematological and Serum Biochemical Parameters in Standing Horses

: Standing sedation is an efficient alternative to general anesthesia in horses and a necessity is present for development of new sedative combinations with minimal adverse effects. Therefore, this study was designed to investigate the effect of xylazine given alone or in combination with fentanyl or nalbuphine on some hematobiochemical parameters in horses. Five adult healthy horses were randomly assigned to receive three treatments at 1 week interval as follows, XYL group (0.55 mg kg G 1 of xylazine IV); XYL/FEN group (0.55 mg kg G 1 of xylazine IV with 4.92 µg kg G 1 of fentanyl IV) and XYL/NAL (0.55 mg kg G 1 of xylazine IV with 0.3 mg kg G 1 of nalbuphine IV).Venous blood samples were collected before (baseline) and at 8, 15, 30, 60, 90 and 120 min after xylazine administration. All studied variables were analyzed using a one-way Analysis of Variance (ANOVA) and the level of significance was set at p<0.05. Significant decrease in Red Blood Cell Count (RBCs), Hemoglobin (Hb) concentrations, Packed Cell Volume (PCV%) was detected the depressant effect of xylazine on red blood cell indices, platelet counts and serum concentrations of TP and albumin, however, fentanyl/xylazine combination may be not recommended in diabetic animals.