Equine Reproduction: Seasonality, Endometritis, and Twinning in the Mare

This chapter reviews the seasonality and effect of photoperiod in mares and how, as clinicians, we can shorten the vernal transition period and improve our efficiency in getting mares in foal. Different protocols have been utilized to shorten the vernal transition, and each will be discussed. We will also examine endometritis in the mare. The role of biofilms in causing endometritis in our equine patients, and potential treatment plans, in particular breeding the dirty mare, will be reviewed. Finally, we will examine the effect of twin pregnancies in the mare, the most common cause of noninfectious abortion, and offer two management therapies for dealing with twinning in the mare.