Doppler ultrasonographic evaluation of ductus venosus blood flow in 55 canine fetuses

PURPOSE: The ductus venosus (DV) blood flow has been studied in fetal lambs and in humans. This study aims to describe the velocities, the Doppler indices and the morphological patterns of the venous blood flow in the DV of canine fetuses during physiological pregnancy. METHODS: The DV of 55 canine fetuses has been evaluated and the waveforms described using B-mode, color and pulsed-wave Doppler ultrasound technology. RESULTS: We found 48 diphasic waves and 7 threephasic waves. No monophasic waveform was found. Six of seven threephasic waveforms belonged to litters in which perinatal mortality occurred. The peak velocity during ventricular systole S (cm/s), the peak velocity during the ventricular diastole D (cm/s), the velocity during atrial contraction aV (cm/s), the S/D index, the pulsatility index (PI) and the resistance index were measured. CONCLUSIONS: All Doppler indices and velocities were significantly correlated with each other (p<0.05). The number of newborn puppies and the age of bitches were not related to DV vascular indices or flow rate (p>0.05). Gestational age was proportional to the PI (p<0.02). Doppler ultrasonography allows the assessment of DV blood flow in canine fetuses during pregnancy.