Pulsed-wave Doppler echocardiography in birds of prey

Pulsed-wave spectral Doppler echocardiography was applied to 111 diurnal and nocturnal raptors of both sexes weighing between 190 and 4200 g. In the first stage, 40 birds were examined without special preparation; in the second stage, 15 birds were examined first when they were not anaesthetised and then when they were anaesthetised; in the third stage, 41 birds were examined after they had been fasted for different periods of time; and finally 15 birds, in which echocardiography had not been possible by using standard (dorsal) restraint and positioning, were examined after being placed in lateral and ventral recumbency. Doppler-derived diastolic inflow into the ventricles was detectable in approximately 80 per cent of the birds weighing between 190 and 2300 g independently of their weight, heart rate and whether they had been anaesthetised or fasted, and aortic blood flow was detected in about 50 per cent of them. It was possible to apply the technique under standard conditions of dorsal recumbency to only one of the birds weighing more than 3000 g and to about 80 per cent of those weighing between 190 and 2300 g. In 11 of 15 birds in which the technique could not be applied under standard conditions, blood flow could be detected in the ventricles and/or the aorta after the birds had been repositioned. No systolic blood flow through the pulmonary artery was detectable in any of the birds.