Gonadotropin regimen for inducing ovarian activity in captive wild felids

Five species of felids (cheetah, North Chinese leopard, tiger, lion, and puma) were serially injected with a source of follicle-stimulating hormone (FSH) to evaluate its effect on ovarian activity. Animals were subjected to laparoscopy before and after gonadotropin treatment, and the number and appearance of mature ovarian follicles (MF), corpora hemorrhagica (CH), and corpora lutea (CL) were recorded and photographed. Ovarian morphologic features, including MF, CH, and CL anatomy, were similar among various species. A dosage of 10 mg of FSH given IM daily for 3 to 5 days was effective in stimulating ovulation in 8 of 8 cheetahs. The same dosage for 5 days stimulated ovulation in 6 of 7 North Chinese leopards, 4 of 7 tigers, 2 lions, and 1 puma. An injection of a luteinizing hormone source was not required to induce follicular rupture. The number of ovulations eventually obtained appeared related to the activity prior to FSH treatment. Females with evidence of follicular development prior to treatment eventually produced a combined average (+/- SEM) of 5.2 +/- 1.3 CH and CL, in comparison with 2.3 +/- 0.8 CH and CL observed in cats with no identifiable follicles before FSH injection. The species varied in the number of ovulation sites (combined number of CH and CL) after treatment, with the cheetahs, leopards, tigers, lions, and puma producing a mean of 5.5 +/- 0.9, 1.5 +/- 0.2, 4.7 +/- 3.1, 1.5 +/- 0.5, and 3.0 +/- 0.0, respectively. The cheetahs, North Chinese leopards, and tigers failed to develop a refractory response to the gonadotropin, as certain females receiving FSH twice at a 1-year interval produced a similar ovulatory response.