Butorphanol with oxygen insufflation corrects etorphine-induced hypoxaemia in chemically immobilized white rhinoceros ( Ceratotherium simum ) (BMC Veterinary Research)

Background: Opioid-induced immobilization is associated with severe respiratory depression in the white rhinoceros. We evaluated the efficacy of butorphanol and oxygen insufflation in alleviating opioid-induced respiratory depression in eight boma-managed rhinoceros. Results: Chemical immobilization with etorphine, azaperone and hyaluronidase, as per standard procedure for the white rhinoceros, caused severe respiratory depression with hypoxaemia (PaO2?=?27???7?mmHg [mean???SD]), hypercapnia (PaCO2?=?82???6?mmHg) and acidosis (pH =7.26???0.02) in the control trial at 5?min. Compared to pre-intervention values, butorphanol administration (without oxygen) improved the PaO2 (60???3?mmHg, F (3,21) =151.9, p