Evaluation of endometrial vascular flow index and echogenicity following experimental induction of subclinical endometritis in dairy cows

This study was conducted aiming to investigate impacts of experimentally induced endometritis on the vascular perfusion and echogenicity of the endometrium in dairy cows. Following estrus synchronization and applying cytological and bacteriological examinations, Holstein cows (n = 9) were enrolled in the experiment. The endometrial blood flow and echogenicity in the middle of each uterine horn were evaluated two times a week until the subsequent estrus by power Doppler and two dimensional ultrasonography. On days 3 and 4 of the subsequent estrous cycle, 15 milliliters of a suspension containing pure culture of Truperella pyogenes (8-15 × 10⁸ cfu/mL) were inoculated into the body of uterus, and then endometrial blood flow and echogenicity were evaluated according to the applied procedure of the previous cycle. The provided results indicated different vascular perfusion and echogenicity among various days of normal estrous cycle, while after induction of endometritis, no significant difference observed. Comparing vascular perfusion between the normal and infectious estrous cycles also revealed significant difference in days 3, 10 and day 14 of two cycles. The differences of endometrial echogenicity between days 3 and 10 of normal and infectious estrous cycle were also significant. In conclusion, inducing endometritis significantly altered pattern of vascular perfusion and echogenicity of uterine horn during certain days of the estrous cycle.