Fecal progesterone and estrogen metabolite monitoring for cyclicity and pregnancy in southern tamandua ( Tamandua tetradactyla )

Reproductive management of the southern tamandua ( Tamandua tetradactyla ) should include timed introductions for breeding to minimize aggression and pregnancy monitoring. Since serial blood sampling could cause unnecessary stress, and urinary progesterone metabolites are found in very low concentrations, this study sought to validate progesterone and estradiol enzyme immunoassays for measuring fecal progesterone metabolite (FPM) and fecal estrogen metabolite (FEM) concentrations in two females. Peaks in FEM concentrations coincided with breeding and conception, were 5–6 times higher than baseline concentrations, and were followed by clear luteal phases distinguished by FPM concentrations 5–6 times higher than baseline concentrations. FPM concentrations during the first 30–53 days of gestation overlapped with luteal phase concentrations, thereafter increasing to 8–25 times higher than baseline concentrations. FEM concentrations during the first 41–44 days of gestation remained near basal values for one female, whereas concentrations were 1.8 times higher than baseline for the second. FEM concentrations became elevated for the former by 44 days of gestation and increased further for the latter after 53 days, ultimately averaging four times higher than baseline for both females. The biphasic increase in FPM and FEM concentrations, follicular and luteal phase durations (follicular: 7 ± 1 days, luteal: 25 ± 1 days), total cycle length (41 ± 1 days), and gestation (161–165 days) documented in this study were consistent with previous reports from serum and urine analyses. Monitoring FPM and FEM is a reliable noninvasive method for tracking reproductive cycles and pregnancy in southern tamandua that overcomes the challenges associated with serum or urinary hormone analysis.