Efforts to induce estrus in the bitch, using pituitary gonadotropins

Induction of fertile estrus in 14 anestrous bitches was attempted, using pituitary gonadotropins given by intramuscular injection in 3 treatment regimens: as a single dose of 10-mg follicle stimulating hormone (FSH; 5 bitches), as multiple doses of FSH (1, 2, 4, 8, 16 mg) given to 4 bitches on days 1 and 2, 3 and 4, 5 and 6, 7 and 8, and 9 and 10, and as multiple doses of combined FSH and luteinizing hormone (LH; 1:1, 1:1, 2:1, 4:1, 8:2.5, 16:5 mg) given to 5 bitches on days 1, 3, 5, 7, 9, and 11, respectively. Four bitches were injected with equivalent volume of isotonic NaCl solution (saline). Treatments were evaluated by observation of sexual behavior in presence of a male, microscopic changes in exfoliated vaginal epithelium, plasma concentrations of estradiol-17 beta and progesterone, and qualitative and quantitative, gross and microscopic changes in the ovaries and uterus. Four of the 14 treated bitches came into estrus and mated (one became pregnant), two after single, and two after multiple doses of FSH. In each of the four, vaginal cornification, plasma estradiol and progesterone patterns, and ovarian and uterine changes were comparable with those seen in the one saline-treated bitch with a spontaneous estrous cycle and pregnancy. Three treated bitches manifested proestrous behavior (2 after a single injection and 1 after multiple injections of FSH) but had no measurable response in the vaginal epithelium, endocrine patterns, or appearance of ovaries and uterus. Seven gonadotropin-treated bitches and 3 saline-treated bitches did not respond in any way.(ABSTRACT TRUNCATED AT 250 WORDS)