Non-invasive fecal steroid analyses were used to characterize gonadal activity in the fishing cat (Prionailurus viverrinus). Estrogen, progestagen and androgen metabolites were quantified in fecal samples collected for 12 months from four males and 10 females housed at seven North American zoological institutions. Male reproductive hormone concentrations did not vary (P > 0.05) among season and estrogen cycles were observed year-round in females and averaged (± s.e.m.) 19.9 ± 1.0 days. Mean peak estrogen concentration during estrus (460.0 ± 72.6 ng/g feces) was five-fold higher than baseline (87.3 ± 14.0 ng/g feces). Five of seven females (71.4%) housed alone or with another female demonstrated spontaneous luteal activity (apparent ovulation without copulation), with mean progestagen concentration (20.3 ± 4.7 μg/g feces) increasing nearly five-fold above baseline (4.1 ± 0.8 μg/g feces). Non-pregnant luteal phase averaged 32.9 ± 2.5 days (n = 13). One female delivered kittens 70 days after natural mating with fecal progestagen concentrations averaging 51.2 ± 5.2 μg/g feces. Two additional females were administered exogenous gonadotropins (150 IU eCG; 100 IU hCG), which caused fecal estrogens to increase and ovulation to occur in both based on elevated fecal progestagen. Results indicate that: (1) male and female fishing cats managed in North American zoos are reproductively active year round; (2) 71.4% of females experienced spontaneous ovulation; and (3) females are responsive to exogenous gonadotropins for ovulation induction, but a regimen that produces a normative ovarian steroidogenic response needs to be identified.
