Aglepristone is a safe abortifacient in cats, dogs and rabbits. Although no serious side effects have been reported, there is no information available about the effects of the medicine on haematological parameters. For the first time clinical and ultrasonographic features and haematological profiles were evaluated in rabbits treated with aglepristone 15 and 16 days after mating. Ten healthy 10-14 month-old New Zealand White female rabbits were mated with fertile bucks and pregnancies were confirmed by ultrasound 15 days later. Of these, 5 does were treated with aglepristone (test group, n = 5) whilst the remaining five (control group, n = 5) were treated with a saline solution (0.9% NaCl). The treatment dose was 10 mg/kg body weight, administered subcutaneously once daily on two consecutive days (day 15 and 16 post mating). Ultrasonographic, clinical and haematological assessments were performed daily. Aglepristone treatment induced embryonic fluid resorptions without foetal death in mid-gestation terminations. Following ultrasonographic and haematological examinations, it was established that aglepristone is a safe abortifacient in rabbits.

Aromatase was localized in the porcine placenta by immunohistochemistry during the first peak of maternal estrogen concentrations (D25; n=3), their nadir around midgestation (D50; n=3) and their second increase in late gestation (D110; n=3). On D25, aromatase was highly expressed throughout the trophoblast. On D50, its expression was restricted to the trophoblast lining the trough-like fossal regions between the bases of chorionic folds. However, immunostaining was detected only in a minor proportion of these locations, with staining intensity being generally only weak to moderate. On D110, distinct to intense immunostaining was found in virtually all trophoblast fossal regions and in similar structures at the flanks of chorionic folds adjacent to the free margins of secondary and tertiary endometrial folds. A weak staining of questionable specificity was occasionally observed in endometrial glands. In other cell types of the utero-placental compartment, aromatase was undetectable. The results suggest that in pigs placental estrogens could be involved in the formation of a more complex geometry of the feto-maternal interface as pregnancy progresses.