Malignant hyperthermia and capture myopathy are two well-described potentially fatal hypermetabolic syndromes described in animals. Several similar conditions known in humans are triggered by severe stress. This report describes a delayed fatal outcome of an injectable anaesthesia in two Mangalica pigs, where hypermetabolism is suspected to have played an important role. The course of events and the results of the investigations do not completely fit with one of the two well-known hypermetabolic syndromes. This suggests that variations of the known pathologies exist and that delayed onset might interfere with potentially successful treatment. Combinations of several risk factors like stress susceptibility, ambient temperature, anaesthetic protocol and potentially a genetic predisposition might have triggered a disturbance of metabolic processes in the animals described in this report.