November 2023 35 Technical I Article o It is excreted through the kidneys and recovery time is prolonged and variable. o Dose 20-50mg/kg I/M or IV • Xylazine o When used alone, xylazine does not usually produce adequate surgical immobilization. o May be associated with bradycardia, hypotension, arrhythmias and respiratory depression. o It frequently causes salivation, excitement, muscle tremors and convulsions, sometimes aggravated by noise o Prolonged recovery, but can be reversed by yohimbine hydrochloride (0.11 – 0.27mg/kg) o Dose 1mg/kg I/M • Xylazine-Ketamine o This combination is commonly used for restraint and anaesthesia but waterfowl (especially ducks and Canada geese), owls and accipiters do not respond well. o When used together the combination is synergistic, giving a smooth induction and recovery with improved muscle relaxation and possibly enhanced analgesia. o Can be associated with cardiac arrhythmias and hypotension o Dose: Ketamine 5-20mg/kg; xylazine 0.5-2.0mg/kg I/M, I/V • Diazepam o By itself, used for sedation or seizure control o Dose 0.05 – 0.15 mg/kg slowly IV, or 0.2 – 0.5 mg/kg I/M • Diazepam – Ketamine o Can be used as an intravenous induction agent in large ratites, raptors and waterfowl, but may not be a reliable maintenance agent. o Can be used intramuscularly in psittacines and pigeons, with a slow induction and recovery time. o Dose: Diazepam 0.2-2mg/kg; Ketamine 10-40mg/kg • Midazolam o Can be used as a sedative and anxiolytics, or as a premedication for anaesthesia o At sedative doses it has minimal effects on blood pressure, heart rate, and body temperature o Dose 0.8 – 3mg/kg IM, IV • Midazolam-Ketamine o Dose: Midazolam 0.2-4 mg/kg; Ketamine 10-40mg/kg IM • Medetomidine-Ketamine o Useful combination for intravenous induction of waterfowl o Rapid induction and recovery o Reversible with atipamezole o Dose: Medetomidine 60-85ug/kg; Ketamine 1.5-2.0mg/ kg • Zolazepam-tiletamine o Not recommended in birds due to violent recoveries • Propofol o Can be used as an intravenous induction agent following sedation with medetomidine-ketamine. o Apnoea is common following IV induction o Dose 1-5mg/kg IV. Intubation and IPPV strongly recommended. Anaesthetic technique – preparation, induction, maintenance, support, monitoring and recovery Patient preparation • Obtain an accurate weight of the patient. • Fast psittacines for no more than 3-4 hours. Larger birds, especially raptors, may require periods of fasting up to 12 hours. • Assess patient’s respiration by distant examination. Look for mouth breathing, tail bobbing, bilateral wing drooping and exaggerated sternal lift as evidence of dyspnoea. If present, this must be factored into the anaesthetic plan, or the anaesthesia postponed. • Palpate the patient’s crop and abdomen o If the crop is full, it must be emptied by crop gavage o If there is abdominal distension it must be determined if there is ascites present. If so, pre-anaesthetic coeliocentesis may be advantageous >>> 36 This article is sponsored by V-Tech
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