CARDIOPULMONARY AND STRESS RESPONSES OF XYLAZINE, ACEPROMAZINE OR MIDAZOLAM SEDATED WEST AFRICAN DWARF GOATS TO DIFFERENT BODY POSITIONING

Abstract

West African Dwarf (WAD) goats serve as an important source of animal protein, are ubiquitous in rural Nigerian households and often undergo surgical procedures. Induction of general anaesthesia in goats is associated with resultant severe systemic side effects depending on the drug and due to position-induced stress. Information on the responses of sedated WAD goats to different sedatives and varying body positioning is not yet reported. Therefore, the study was designed to investigate cardiopulmonary and stress responses of WAD goats to xylazine, acepromazine or midazolam sedation in different body positioning. Adult WAD bucks (n=6), mean body weight of 11±2.0 kg were randomly selected for three separate experiments using xylazine, acepromazine or midazolam in five clinical trials lasting five days each. Sedation was achieved by intramuscular administration of xylazine (0.05mg/kg), acepromazine (0.2 mg/kg) or midazolam (0.3 mg/kg). For each experiment, goats were restrained in standing (control), Right Lateral (RL), Left Lateral (LL), supine and prone positions. Venous blood (5 ml) via jugular venipuncture was collected before and after each trial to determine selected stress biomarkers [blood glucose (mg/dL), plasma cortisol (mmol/L) and lactate dehydrogenase LDH (U/L)] using specific kits and Autoanalyser®. Heart Rate -HR (beats/minute), Respiratory Rate -RR (breaths/minute), Mean Arterial Pressure -MAP (mmHg), Oxygen-haemoglobin Saturation -SpO2 (%) and Rectal Temperature -RT (°C) were measured at intervals of 10 minutes for one hour using multiparameter monitor®. The bucks were rested for 14 days in between clinical trials. Data were analysed using descriptive statistics and ANOVA at α0.05. In LL, supine and prone body positions, peak blood glucose levels and plasma cortisol, respectively were significantly increased with xylazine (210.8±55.5; 44.0±32.3), acepromazine (121.0±70.4; 137.5±80.2) and midazolam (90.5±40.8; 97.3±31.5) compared to control (78.5±15.4; 14.7±9.1). Plasma levels of LDH (213.7±36.7 to 358.2±96.6) were significantly decreased compared to control (282.3±48.5 to 706.2±711.9) for the RL, LL, supine and prone positions with xylazine and acepromazine sedation. Significant decreases in HR (59.5±8.2 to 65.0±5.8) were observed with xylazine in all the body positions except in prone compared to control (72.4±23.4 to 78.6±31.4), while acepromazine and midazolam had highest HR with supine position. Xylazine sedation increased RR for the LL (37.2±18.9) versus control (30.3±13.9). Acepromazine and midazolam did not show any significant changes in RR for all body positions. Xylazine and acepromazine sedation resulted in significant decrease in MAP for the RL (45.3±19.5 to 70.0±10.5), LL (50.7±5.8 to 64.2±17.8) and supine (42.0±10.6 to 62.5±22.3) positions compared to control (61.3±10.1 to 87.0±10.7). However, midazolam sedation did not show significant changes in MAP in other body positions. No significant decrease was observed for SpO2 and RT with any of the sedatives regardless of body positions.

Xylazine sedation resulted in severe hypotension and hyperglycaemia with left lateral and supine body positions whereas acepromazine and midazolam sedation resulted in mild hypotension and increased heart rate with the left lateral and prone body positions. The left lateral and prone positioning should therefore be avoided in caprine sedation. Acepromazine and midazolam are considered safer alternatives to xylazine for sedation in West African Dwarf goats.