Gonadotropin induced reproductive cyclicity in the domestic cat

Adult queens were treated with one of two sources of follicle stimulating gonodotropin (follicle stimulating hormone or pregnant mares' serum gonodotropin) to induce ovarian follicle development and estrus. Treatment involving single injections of follicle stimulating hormone stimulated mature follicle development but resulted in inconsistent display of sexual receptivity and variable ovulation rates. Single or multiple injections of pregnant mares' serum gonadotropin induced follicel growth, but follicle rupture often occurred prior to estrus and the mating stimulus. When compared to results obtained from queens mated while in natural estrus, cats receiving a series of injections of follicle stimulating hormone or pregnant mares' serum gonadotropin demonstrated ovarian hypersensitivity and produced follicular cysts which failed to rupture. The most effective hormone regimen for inducing follicle growth and estrus consisted of 2.0 mg follicle stimulating hormone injected daily intramuscularly until estrus. Queens receiving this treatment were capable of ovulating following mating or human chorionic gonodotropin administration and were capable of conceiving if mated.