Severe hyperglycaemia associated with prolonged isoflurane anaesthesia in an alpaca (Vicugna pacos)

Alpacas possess distinct glucose and insulin regulatory mechanisms compared with other species, often maintaining higher baseline blood glucose as a normal physiological adaptation. Inhalant anaesthetic agents can further disrupt glucose, insulin and potassium homeostasis, particularly during prolonged procedures. This report describes a 6-year-old male alpaca that developed severe hyperglycaemia during 4.5 hours of isoflurane anaesthesia for surgical removal of a cervical cystic mass. Blood glucose concentrations rose progressively from 202 mg/dL at 40 minutes to a peak of 583 mg/dL at 245 minutes, accompanied by mild elevations in potassium and lactate. Despite these marked metabolic disturbances, the alpaca remained haemodynamically stable, recovered uneventfully, and glucose values returned to reference ranges within 24 hours. This case highlights the importance of monitoring blood glucose and potassium concentrations during prolonged inhalant anaesthesia in alpacas, especially in those with underlying illnesses.