Prebreeding season/prepurchase examination of the stallion: testicular ultrasonography, semen evaluation, and considerations

Abstract

The stallion breeding soundness examination (BSE), as initially contemplated by the Society for Theriogenology, was intended to serve as a tool for selecting stallions that under good breeding management and mare fertility, were expected to efficiently render at least 75% of > 40 mares pregnant when bred naturally or 120 mares when bred artificially in 1 breeding season. Since its initial introduction 38 years ago, major changes in the equine breeding industry have occurred. Yet, the original purpose of the BSE has remained somehow unchanged and a BSE still provides to both practitioners and owners valuable information regarding the reproductive potential of the stallion and reproductive management options that could be implemented for optimizing fertility of a particular stallion. This manuscript discusses some aspects of BSE that warrant special considerations, due to their implementation under field conditions and their interpretation regarding the potential fertility of stallions.