In our last program, we discussed the breeding soundness exam of the mare.  Today we will talk about breeding soundness exam of the stallion because if you have a stallion you want to stand at stud, you certainly want to make sure he is fertile.  The exam will be done after the stallion has had 1 week of sexual rest and will begin by your veterinarian doing a complete physical exam that will focus not only on reproductive areas but also other areas such as lameness.  The external genitalia will be examined and the internal genitalia will be examined rectally.  A culture will be done of the penis and urethra.  Many normal organisms are in this area so a positive culture is probably not important unless pathogenic organisms are identified.  Also, the semen will also be cultured to check for internal genital infections. 

The stud will then be observed for behavior and the ability to physically breed.  Semen will be collected into an artificial vagina two times at a 1-hour interval and analyzed. The semen will be checked for volume, concentration, and motility and the number of progressively motile sperm will be calculated.  This number will be important when we discuss artificial breeding and shipping semen as this determines the number of mares that can be bred with each ejaculate.  Morphology of the sperm will also be examined to check for abnormalities of the sperm cells that could play a role in reduced fertility.  Other tests such as a hormonal or ultrasound exam can be done if deemed necessary.  In general, to be a satisfactory breeding prospect, the stallion must be free of undesirable heritable defects, behavioral disorders, venereal diseases, physical defects that could prevent breeding, and must ejaculate greater than 1 billion progressively motile sperm on the second of two ejaculates collected 1 hour apart.