Research overview: noninvasive hormone monitoring in felid reproduction

Noninvasive measurement of reproductive and stress hormones from feces and urine has transformed the study and management of felid reproduction. This overview surveys the development and application of noninvasive hormone monitoring in cats, including assays for estrogen, progestin, androgen, and glucocorticoid metabolites that allow tracking of cycles, ovulation, pregnancy, and stress without restraint. It reviews how these methods are validated for each species and used to time breeding, diagnose reproductive problems, and assess welfare. The review connects noninvasive monitoring to assisted reproduction and conservation breeding across the cat family. Understanding noninvasive hormone monitoring clarifies the foundational role of endocrine assessment in modern felid reproductive science, enabling detailed physiological study of even dangerous and endangered species.