Intromission failure in a stallion

Determining the cause of poor libido in stallions can be challenging. Many factors can cause disturbance in libido (e.g., lameness or physical pain, hormonal, age, experience, and handling). Identifying the cause of poor libido is important to determine the best treatment approach. A 6-year Thoroughbred stallion was presented for failure of intromission when attempting to breed mares. Stallion was recently retired from racing. Stallion was placed on hormonal therapy that did not change stallion’s aberrant reproductive behavior. On presentation no obvious physical causes were identified and the stallion displayed masturbation behavior. Through the review of video recordings of the breeding sessions, modifications were made that eventually resulted in the stallion successfully breeding mares without hormonal intervention. This case illustrated how video recordings of breeding activity can help in determining cause of reproductive dysfunction. Furthermore, interpretation of peripheral steroid hormone concentrations needs to be carried out with caution.