Can the ovarian blood flow assessed by power Doppler be used in the bitch for monitoring ovulation and luteal phase?

The haemodynamic changes in the ovary of non-pregnant bitchesduring oestrous and diestrous phases were characterized by powerDoppler (PD) to verify the relationship of the perfusion parameterswith ovulation and luteal function assessed by serum progesteroneconcentrations. Eight healthy German Shepherd bitches wererecruited in this study. Intraovarian vascularization was examinedby Colour Doppler (Duplex mode) and PD throughout the oestruscycle, at daily intervals from the onset of proestrus to the first day ofcytological diestrous and then every three days until the end ofdiestrous. During the early proestrous and late estrous phase, the pixelnumber increased progressively from 18059.9 to 3303144.4,respectively. In particular, this increment was significantly higher(p<0.05) just before ovulation (70887.4) and soon after ovulation(3227217.1). Afterwards, the pixel numbers decreased progressivelyuntil the end of observations when the number of pixel returned tobasal values observed during the proestrous phase (15522.7). Themean blood progesterone concentrations and pixel number showed adirect positive correlation. The results of our study show that the PDis valid method for studying the vascularization of the ovary duringthe oestrous cycle in the bitch. In particular, this technique couldprovide another useful method for determining more precisely thetime of ovulation and monitoring luteal function in the bitch