Intrauterine Marbles for Estrus Suppression in Mares - Two Marbles Are Not Always Better Than One

Estrous behavior in performance mares is undesirable (aggression, hyperexcitability, musculoskeletal pain). Methods of estrus suppression include progestin supplementation, administration of oxytocin during diestrus, and intrauterine marbles. Marbles can prolong the luteal phase and decrease behavioral estrus in some mares. The efficacy of intrauterine marbles is debatable and severe complications with their use have been reported. The following describes two separate instances of previously unreported complications associated with intrauterine marbles. [...]