Ovarian Color-Doppler Ultrasonography to Predict Ovulation in the Bitch.

Abstract

Due to the fact that domestic bitches only ovulate once or twice a year and because of variation between and within dogs, a direct, non-invasive and fast technique that will give scientists and practitioners the ability to immediately determine the time of ovulation in a domestic canine model is desirable. At the school of Veterinary Medicine of Louisiana intraovarian blood flow was monitored in 10 bitches using color-coded Doppler ultrasonography to determine the time of ovulation. The bitches were induces with deslorelin (Ovuplant ®) and the estrus cycle was subsequently followed using color Doppler ultrasound, vaginal cytology and progesterone assays. A scoring system for subjective quantitation of vascular perfusion was used, using the extent of involvement from minimal to maximal (scores 1 to 4). During proestrus a gradual increase in color was seen. A marked enhancement of coloring was observed in the preovulatory period and maximal color pixel density was found two days after the day of the LH surge and during the early luteal phase. For days -1 to 2 post LH surge, a significant difference in the distribution of scores across days for the right ovary was found (p < 0.001). In the right ovary, a significant difference was found in the frequency of scores between days -1 and 0 (p < 0.01), days -1 and 2 (p < 0.05) and days 0 and 2 (p < 0.05), with higher scores on day 0 and day 2 than on day -1 and day 0. Color Doppler ultrasonography provides complementary information about cyclic changes within the ovary. A marked increase in blood flow around the LH surge could be associated with the time of ovulation.