title: Estradiol benzoate for preventing pregnancy in mismated dogs.
abstract: We investigated the use of a single treatment of estradiol benzoate (E2B) to prevent pregnancy in mismated dogs, including effects of dose, side effects, and mechanism of action. We used 74 female beagles aged 1-10 year. A single treatment of E2B (0.025, 0.05, 0.10, or 0.20 mg/kg; 10 dogs/dose) given 2 days after mating (5 days after ovulation) resulted in pregnancy rates of 70, 50, 10, and 0%, respectively, whereas pregnancy rate was 100% in 5 untreated (control) dogs. There were no side effects in dogs given E2B, regardless of dose. To clarify the mechanism of prevention of pregnancy, we investigated embryonic descent in the uterine tube and embryonic degeneration after treatment with 0.025 or 0.20 mg/kg of E2B; treatment delayed embryonic descent in the uterine tube and increased the incidence of embryonic degeneration. In conclusion, a single treatment of 0.020 mg/kg of E2B given 2 days after mating effectively and safely prevented pregnancy in dogs.
authors.affiliation: Department of Reproduction, Nippon Veterinary and Animal Science University, 1-7-1, Kyonan-cho, Musashino-shi, Tokyo 180-8602, Japan. tsutsui@nvau.ac.jp
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Tsutsui
authors.forename: Wataru
authors.initials: W
authors.lastname: Mizutani
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hori
authors.forename: Keiko
authors.initials: K
authors.lastname: Oishi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Sugi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Kawakami
mesh_terms: D000818:Animals; D003267:Contraception / Q000379:methods / Q000662:veterinary*; D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D004285:Dogs / Q000097:blood / Q000502:physiology*; D004334:Drug Administration Schedule; D047108:Embryonic Development / Q000187:drug effects; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D011247:Pregnancy; D011374:Progesterone / Q000097:blood
chemical_list: D003271:Contraceptive Agents, Female; C074283:estradiol 3-benzoate; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone