Failure of regression of the cranial gonadal suspensory ligament in a 3 year old male Quarter Horse

Cryptorchidism is the most common developmental defect in the horse (Schambourg, M.A. et al, 2006). Studies have shown 2-8% prevalence for this condition in horses. Cryptorchidism is characterized by failure of one or both testes to descend into the scrotum. Retained testes can be found anywhere between the caudal poles of the kidneys to subcutaneously outside of the body wall, but abdominal retention is the most common presentation (Amann, R.P. and Veeramachaneni, D.N.R., 2007). Normal and disturbed testicular descent is frequently approached exclusively through consideration of the caudal testicular suspensory apparatus. However, embryological gonads develop with both cranial and caudal suspensory ligaments, and the sexes differ in respect to the persistence and development of both the cranial and caudal ligaments (Van Der Schoot, P. and Elger, W., 1992). The following case report illustrates an atypical case of bilateral abdominal cryptorchidism. "Starham's Yellow Brick", a 3 year old male Quarter Horse that presented to the Cornell University Hospital for Animals for persistence of stallion-like behavior despite previously reported castration. Upon physical examination, testes could not be seen or palpated within the scrotum. After performing an hCG stimulation test and measuring testosterone, the diagnosis of cryptorchidism was made. Laparoscopic abdominal exploratory with the horse in dorsal recumbency was unsuccessful in locating the testis. Bilateral exploratory flank celiotomies were then performed and the testes were located and removed from an unusual anatomical position