Equine Genital Abnormalities of the Stallion – NAVLE Study Guide

Overview and Clinical Importance

Genital abnormalities of the stallion encompass a spectrum of congenital and acquired conditions affecting reproductive function. Cryptorchidism is the most common developmental disorder of the male reproductive tract, affecting 2-8% of male horses. Understanding these conditions is essential for the NAVLE, as they frequently appear in clinical scenarios involving breeding soundness examinations, behavioral problems in supposed geldings, and surgical decision-making.

This guide covers the major categories of stallion genital abnormalities including cryptorchidism, penile and preputial disorders, testicular conditions, and inguinal hernias. Each condition is reviewed with emphasis on etiology, clinical presentation, diagnostic approach, and treatment options relevant to NAVLE preparation.

Cryptorchidism

Cryptorchidism (from Greek: kryptos = hidden, orchis = testis) refers to the failure of one or both testes to descend into the scrotum. It is the most common disorder of sexual development in male horses, with a prevalence of 2-8% in the general population.