Evaluation of medetomidine-ketamine and dexmedetomidine-ketamine in Chinese water deer (Hydropotes inermis)

Objective To investigate physiological and sedative/ immobilization effects of medetomidine or dexmedetomidine combined with ketamine in free-ranging Chinese water deer (CWD). Study design Prospective clinical trial. Animals 10 free-ranging adult Chinese water deer (11.0 +/- 2.6 kg). Methods Animals were darted intramuscularly with 0.08 +/- 0.004 mg kg(-1) medetomidine and 3.2 +/- 0.2 mg kg(-1) ketamine (MK) or 0.04 +/- 0.01 mg kg(-1) dexmedetomidine and 2.9 +/- 0.1 mg kg(-1) ketamine (DMK) If the animal was still laterally recumbent after 60 minutes of immobilization, atipamezole was administered intravenously (MK: 0.4 +/- 0.02 mg kg(-1), DMK: 0.2 +/- 0.03 mg kg(-1)). Heart rate (HR) respiratory rate (f(R)) and temperature were recorded at 5-minute intervals. Arterial blood was taken 15 and 45 minutes after initial injection. Statistical analysis was performed using Student's t-test or ANOVA. p < 0.05 was considered significant. Results Animals became recumbent rapidly in both groups. Most had involuntary ear twitches, but there was no response to external stimuli. There were no statistical differences in mean HR (MK: 75 +/- 14 beats minute(-1); DMK: 85 +/- 21 beats minute(-1)), f(R) (MK: 51 +/- 35 breaths minute(-1); DMK; 36 +/- 9 breaths minute(-1)), temperature (MK: 38.1 +/- 0.7 degrees C; DMK: 38.4 +/- 0.5 degrees C), blood gas values (MK: PaO2 63 +/- 6 mmHg, PaCO2 49.6 +/- 2.6 mmHg, HCO3- 30.8 +/- 4.5 mmol L-1; DMK: PaO2 77 +/- 35 mmHg, PaCO2 45.9 +/- 11.5 mmHg, HCO3- 31.0 +/- 4.5 mmol L-1) and biochemical values between groups but temperature decreased in both groups. All animals needed antagonism of immobilization after 60 minutes. Recovery was quick and uneventful. There were no adverse effects after recovery. Conclusion and clinical relevance Both anaesthetic protocols provided satisfactory immobilisation. There was no clear preference for either protocol and both appear suitable for CWD