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 (±SEM) 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 g/g feces), increasing nearly five-fold above baseline (4.1
±
0.8 g/g
feces). The 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 g/g feces. Two additional females were administered exogenous gonadotropins
(150 IU eCG; 100 IU hCG), which caused hyper-elevated concentrations of fecal estrogen
and progestagen (plus ovulation). 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.