title: Control of reproduction with anti-progestin and oestrogens in captive bears.
abstract: The aim of this study was to establish new methods for controlling reproduction in bears. Anti-progestins were used to interrupt pregnancies. In two consecutive years, the anti-progestin J956 was administered to 11 female bears (nine Ursus arctos, one Ursus tibethanus, one Tremarctos ornatus) living in zoos. The anti-progestin J956 was given orally (n = 4) or parenterally (n = 12). The anti-progestin was administered alone or in combination with ethinyloestradiol, and before or after embryo implantation. The effects of anti-progestin treatment were determined using ultrasonographic examination of the urogenital tract and by monitoring progesterone concentrations in the blood and faeces. Oral administration of anti-progestin was not successful (successful in 0 of 4); however, in contrast, none of the parenteral treated animals remained pregnant (successful in 12 of 12). Parenteral treatment with J956, with or without ethinyloestradiol, was effective in disrupting pregnancy before implantation (successful in 6 of 6) and after implantation (successful in 6 of 6), but administration one month after implantation (n = 2) resulted in incomplete resorption of the fetuses. In conclusion, the administration of anti-progestins may be a useful method for preventing embryo implantation in captive bears.
authors.affiliation: Institute for Zoo Biology and Wildlife Research, PF 601103, D-10252 Berlin, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Göritz
authors.forename: M
authors.initials: M
authors.lastname: Quest
authors.forename: T
authors.initials: T
authors.lastname: Hildebrandt
authors.forename: H H
authors.initials: HH
authors.lastname: Meyer
authors.forename: L
authors.initials: L
authors.lastname: Kolter
authors.forename: W
authors.initials: W
authors.lastname: Elger
authors.forename: K
authors.initials: K
authors.lastname: Jewgenow
mesh_terms: D000019:Abortifacient Agents / Q000008:administration & dosage*; D000028:Abortion, Induced / Q000662:veterinary*; D000034:Abortion, Veterinary; D000284:Administration, Oral; D000818:Animals; D000836:Animals, Zoo; D010064:Embryo Implantation / Q000187:drug effects; D010065:Embryo Implantation, Delayed / Q000187:drug effects; D004963:Estrenes; D004997:Ethinyl Estradiol / Q000008:administration & dosage; D005260:Female; D007263:Infusions, Parenteral; D010091:Oximes / Q000008:administration & dosage*; D010120:Oxytocics / Q000008:administration & dosage*; D011247:Pregnancy; D011374:Progesterone / Q000037:antagonists & inhibitors*; D016216:Ultrasonography, Prenatal / Q000662:veterinary; D001503:Ursidae
chemical_list: C446760:4-(17beta-methoxy-17alpha-(methoymethyl)-3-oxoestra-4,9-dien-11beta-yl)benzaldehyd-1-(E)-(O-(ethylamino)carbonyl)oxime; D000019:Abortifacient Agents; D004963:Estrenes; D010091:Oximes; D010120:Oxytocics; D004997:Ethinyl Estradiol; D011374:Progesterone