Estrus

Disease Overview

Left to her own devices, a mare’s reproductive cycle will usually follow the rhythms of nature, with estrus (fertility and sexual receptivity) occurring during spring and summer when the daylight hours are long and anestrus (sexual inactivity) corresponding with the dark winter months. Horse owners and handlers may want to manipulate natural estrus for a number of reasons.

For example, sexual behavior or estrus-related “moodiness” may be undesirable in performance horses or a breeding facility may want breeding’s to follow a predictable schedule for management reasons. Suppression of estrus can help achieve these goals safely and predictably.