EN
The aim of this work was to investigate the efficacy of aglepristone in three different doses used to terminate pregnancy 21-24 days after mating in female cats. Cats (n = 43) were divided into three groups with 14 cats in each group and one female cat was described separately. Aglepristone was injected twice, 24 h apart. Female cats in group I received 10 mg/kg subcutaneously (sc), in group II - 12.5 mg/kg sc and in group III - 15 mg/kg. Termination of pregnancy was successful in 9 female cats (64.3%) in group I, seven of which had absorbed embryo and two aborted lifeless fetuses. Four female cats gave birth to healthy kittens between days 62 and 65 of pregnancy. The last female cat gave birth to one live kitten on day 62 of pregnancy post treatment after an ultrasound examination revealed 4 embryos. In group II pregnancy was terminated in 12 female cats (85.7%), 10 of them absorbed embryos and two aborted lifeless fetuses between days 36 and 45 of pregnancy. The remaining two gave birth to live kittens between day 62 and 64 of pregnancy. In group III pregnancy was terminated in 13 female cats (92.8%), 12 of which absorbed embryos and one aborted three lifeless fetuses. The last female cat, post treatment, gave birth to one live kitten on day 61 of pregnancy after ultrasound evaluation showed 5 embryos. This kitten died within 3 days of life. One owner gave her pregnant cat a medroxyprogesterone acetate injection, and although the female cat also receive aglepristone at a dose of 20 mg/kg, she gave birth to two live kittens. The progesterone concentrations were within reference values in the examined groups and increased after the injection of aglepristone. The results indicate that none of the doses of aglepristone used were 100% successful clinically, however the most effective dose was 15 mg/kg. Pruritus at the site of injection immediately after injection was the most common side effect noticed.