Physiologic And Blood Gas Effects Of Xylazine-Ketamine Versus Xylazine-Tiletamine-Zolazepam Immobilization Of White-Tailed Deer Before And After Oxygen Supplementation: A Preliminary Study

Objective To compare oxygenation and ventilation in white-tailed deer (Odocoileus virginianus) anesthetized with two treatments with and without oxygen supplementation.Study design Randomized, blinded, crossover study.Animals A total of eight healthy adult white-tailed deer weighing 49-62 kg.Methods Each deer was anesthetized twice intramuscularly: 1) treatment XK, xylazine (2 mg kg(-1)) and ketamine (6 mg kg(-1)) and 2) treatment XTZ, xylazine (2 mg kg(-1)) and tiletamine-zolazepam (4 mg kg(-1)). With the deer in sternal position, arterial and venous blood was collected before and at 30 minutes during administration of oxygen at 1 L minute(-1) through a face mask. PaO2 and heart rate (HR) were compared using two-way repeated measures ANOVA. pH, PaCO2 and lactate concentration were analyzed using mixed-effects linear models, p < 0.05.Results When breathing air, PaO2 was < 80 mmHg (10.7 kPa) in six and seven deer with XK and XTZ, respectively, and of these, PaO2 was < 60 mmHg (8.0 kPa) in three and five deer, respectively. With oxygen supplementation, PaO2 increased to 128 +/- 4 and 140 +/- 5 mmHg (17.1 +/- 0.5 and 18.7 +/- 0.7 kPa), mean +/- standard error, with XK and XTZ, respectively (p < 0.001). PaO2 was not significantly different between treatments at either time point. HR decreased during oxygen supplementation in both treatments (p < 0.001). Lactate was significantly lower (p = 0.047) with XTZ than with XK (2.2 +/- 0.6 versus 3.5 +/- 0.6 mmol L-1) and decreased (p < 0.001) with oxygen supplementation (4.1 +/- 0.6 versus 1.6 +/- 0.6 mmol L-1). PaCO2 increased in XTZ during oxygen breathing.Conclusions and clinical relevance Treatments XK and XTZ resulted in hypoxemia, which responded to oxygen supplementation. Both treatments are suitable for immobilization of white-tailed deer under the study circumstances.