Ultrasonographic monitoring of the pregnant bitch is an established routine in many veterinary clinics. In order to better assess foetal health and avoid pregnancy losses, Doppler ultrasonographic evaluation of the pregnant uterus is the need of the day. Investigations on the dynamics of maternal and foetal blood flow using Doppler ultrasound have been conducted in multiple species recently and it is invisaged that it would be a reliable diagnostic tool in future in monitoring pregnancy. The present study was designed to compare Doppler parameters systolic peak velocity (SPV), end diastolic velocity (EDV), pulsatility index (PI) and resistivity index (RI) of the uteroplacental (UPA) and umbilical arteries (UA) measured during 40 to 50 and 51 to 60 days in normal gestation and threatened abortion in canines. In total 40 pregnant bitches with known history of breeding; irrespective of age and parity belonging to different breeds were classified into normal gestation (NG) and threatened abortion (TA). Bitches with the history of greenish black discharge or expulsion of one foetus were included in the abortion group and bitches with no such symptoms were included in the normal gestation group. End diastolic velocity of uteroplacental vessels decreased while PI and RI increased significantly with decrease in body weight in threatened abortion cases during 40 to 50 and 51 to 60 days of gestation in canines. Systolic peak velocity and EDV of umbilical arteries increased while PI decreased significantly with decrease in body weight during 40 to 50 days of gestation in canine threatened abortions. Doppler evaluation of uteroplacental and umbilical arteries is recommended as a diagnostic tool to monitor high risk pregnancy during 40 to 50 and 51 to 60 days of gestation in canines.

中文翻译：

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多普勒评估正常妊娠母体血管和犬先兆流产。

怀孕母犬的超声监测是许多兽医诊所的既定常规。为了更好地评估胎儿健康并避免流产，多普勒超声评估妊娠子宫是当务之急。最近已经在多个物种中使用多普勒超声对母体和胎儿血流动力学进行了调查，预计这将成为未来监测妊娠的可靠诊断工具。本研究旨在比较子宫胎盘 (UPA) 和脐动脉 (UA) 在 40 至正常妊娠 50 天和 51 至 60 天，犬先兆流产。共有 40 只已知繁殖历史的怀孕母犬；不分年龄和胎次，属于不同品种，分为正常妊娠（NG）和先兆流产（TA）。流产组包括有绿黑色分泌物或一个胎儿排出史的母犬，正常妊娠组包括无此类症状的母犬。在先兆流产病例中，犬在妊娠 40 至 50 天和 51 至 60 天期间，子宫胎盘血管的舒张末期速度降低，而 PI 和 RI 随体重的降低而显着增加。在犬先兆流产的妊娠 40 至 50 天期间，随着体重的减少，脐动脉的收缩峰值速度和 EDV 增加而 PI 显着降低。