Doppler ultrasounography of the aorta, common carotid artery and fetal renal artery during dogs pregnancy of French Bulldog breed bitches underwent caesarean delivery

The prediction of fetal development complications in dogs is relevant to eventual post-partum management decisions or to establish caesarean intervention protocols. French Bulldog bitches often develop complications that hinder natural delivery. In such circumstances the establishment of fetal viability is fundamental. Twenty-six French bulldog bitches with average weight of 20 ± 2,80kg and average age between 3 and 5 years, were evaluated by doppler ultrasound for measurement of the vascular flow patterns of fetal aorta (AOfet), fetal common carotid artery (CCAfet) and right and left fetal renal artery (RAfetD and ARfetE). Vascular flow values were correlated with the average heart rate of the animals studied. The equipment used for this study was a SonoSite ultrasound M-Turbo (USA, Washington), coupled to sectoral (5-8 mHz) and linear probes (12-15mHz). The calculations of gestational ages were performed automatically by measuring the biparietal diameter and abdominal diameter (tables inserted in the data platform by the authors). The vascular flow measurements were made by adjusting the pulse repetition frequencies (PRF) of each vessel studied as well as maintaining an insonation angle smaller than 20. The systolic flow velocities (SFV), resistivity index (RI) and heart rate (HR) were presented as follows: (a) after 28 days of pregnancy – HR= 245±3.45 bpm, AOfet, VSF=31±1.14cm/s, RI= 0.94±0.06; CCAfet, VSF=39±1.16cm/s, RI= 0.81±0.01. (b) 40 days of pregnancy – HR= 235±2.73 bpm, AOfet, VSF=48±1.2cm/s, RI= 0.92±0.09; CCAfet, VSF=42±1.14cm/s, RI= 0.72±0.03, ARfetD, VSF=28±2.16cm/s, IR= 0.70±0.05; RAfetE, VSF=29±2.10cm/s, RI= 0.71±0.02. (c) after 56 days of pregnancy – HR= 215±1.60 bpm, AOfet, VSF=57±1.19cm/s, RI= 0.81±0.01; CCAfet, VSF=45±2.11cm/s, RI= 0.61±0.02; RAfetD, VSF=37±1.21cm/s, RI= 0.72±0.07; RAfetE, VSF=39±1.11cm/s, IR= 0.73±0.05. There was no difference between the means of right and left renal arteries (p>0.05). The monitoring of AOfet, CCAfet and RAfet flows allowed us to suggest the normal vascular flow values during gestation of French Bulldog bitches underwent caesarean delivery. There was no alteration in the puppies viability and there were no complications or death during the procedure neither in post-partum. Thus, we suggest these hemodynamic values as a starting point for investigation of fetal hemodynamic complications during parturition, such as fetal stress in French Bulldog breed underwent caesarean delivery.