Research overview: fecal estrogen monitoring to track estrus in felids

Measuring estrogen metabolites in feces allows researchers to follow follicular development and estrus in cats without restraint or blood collection. This overview describes how fecal estrogen profiles rise during the follicular phase and fall after ovulation, providing an objective marker of estrous timing in species that show little behavioral signaling. It reviews how these assays are validated for individual species and used to detect cycling, predict receptive periods, and schedule artificial insemination. The noninvasive nature of the method makes it especially valuable for endangered and dangerous felids. By translating hormone patterns into actionable timing, fecal estrogen monitoring has become a routine tool in conservation breeding and reproductive research across the cat family.