Anton Antonov, Plamen Georgiev, Julieta Dineva, Theresa Conze, Radostina Dimitrova, Axel Wehrend


The aim of our study was to investigate the effects of the antiprogestin aglepristone after its application in bitches with high serum progesterone concentrations on some specific vaginal parameters. Twelve non-pregnant female dogs from different breeds and ages were included in the study. The bitches were divided into two groups. Group I (n = 6) received aglepristone (10 mg/kg, subcutaneously) injected twice, 24 h apart, on days 29 and 30 after the estimated day of ovulation, which was determined by progesterone assays. Group II (n = 6) served as a control group and received a placebo. The electrical resistance of vaginal mucus, vaginal pH and serum P4 levels were determined on days 29, 30, 33, 36, 39, 42 and 45 after ovulation. Additionally, vaginal smears were performed to evaluate the changes in vaginal cells. Partial luteolysis was detected at day 32.5 ± 2.26 (mean ± SD) and 44 ± 1.73 in treated and control bitches, respectively (p < 0.001). Complete luteolysis (P4 < 2 ng/ml) was observed on day 41.5 ± 2.26 in treated bitches. Beginning on the day after the first treatment, a decrease in electrical resistance of vaginal mucus was measured in the experimental group. A significant reduction (p < 0.05) occurred on day 41.5±2.26 compared with day 29. The pH of vaginal secretions of all bitches in Group I increased during the period starting from the day after the first treatment. A significant difference (p < 0.05) was found on day 32.5 ± 2.26. No changes were detected for either parameter in the control group. The cell populations in vaginal smears of all animals were similar. In conclusion, aglepristone administration to dogs during the mid-luteal stage influenced vaginal pH and the electrical resistance of vaginal mucus.

Key words: vagina; bitch; aglepristone; electrical resistance; pH

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