Cryptorchidism in stallions

Abstract

Cryptorchidism is the most common disorder of sexual development in the male. The etiopathogenesis of cryptorchidism remains poorly understood and may involve genetic and environmental factors. The condition is obvious in horses with a good history, but diagnosis of cryptorchidism can be challenging in an apparently gelded horse presenting with stallion-like behavior and hemicastrated horses. Determination of the location of the retained testis is important for the selection of the surgical approach for cryptorchidectomy. The objective of this paper is to review current knowledge regarding pathogenesis of cryptorchidism in the equine, and methods for diagnosis including ultrasonographic determination of the location of the retained testis. A discussion of cryptorchidectomy approaches and possible complications is presented.

Expression pattern of germ cell markers in cryptorchid stallion testes

“…We found the STs in the CST group were small, there was no spermatogenic activity, and the tubule contained a single vacuole with Sertoli cells, spermatogonia and occasionally early spermatocytes. Our histopathology results obtained from HE staining are consistent with previous studies where STs in cryptorchid stallions exhibit a vacuolation of cells with a wider lumen (Arroyo & Tibary, 2023;Rode et al, 2015). The differentiation and proliferation of somatic and germ cells in cryptorchid testis were adversely affected by elevated temperatures.…”

“…When unilateral cryptorchid horses are sold as geldings, hemicastration is highly discouraged, and using unilateral cryptorchid stallions is not recommended during breeding programme (Arroyo & Tibary, 2023). Moreover, unlike other domestic species, stallions selected for breeding are primarily judged by their track record and conformation rather than their reproductive soundness and heritable traits, resulting in low fertility indices and conception rates per cycle (Nath et al, 2010).…”

Diagnostic Approach to Equine Testicular Disorders

“…False negatives have been reported and are attributed to insufficient number or degeneration of Sertoli cells [41]. Although the diagnosis of cryptorchidism can be established by endocrine testing, clinical evaluation and the determination of the location of the retained testis are required before surgery [58,66]. This allows the evaluation of testicular tissue for any pathology and the selection of the best surgical approach based on location.…”

“…the vas deferens is identified and followed on each side toward the inguinal area (Figure 12) [58,69,70].…”

“…Failure to locate the retained testicles despite using a combination of palpation, transcutaneous, and transrectal ultrasonography is possible when there is true monorchidism or severe ischemic necrosis of the retained testis [58]. the vas deferens is identified and followed on each side toward the inguinal area (Figure 12) [58,69,70].…”