Clinical Course of Severe Perineal Hypospadias with Cryptorchid Testicular Tumors in a Dog: Contextual Reference to Developmental and Endocrine Transcriptomic Pathways.

Hypospadias is a congenital malformation of the male external genitalia resulting from incomplete fusion of the urethral folds during embryonic development. The perineal form represents the most severe phenotype and is frequently associated with abnormalities such as cryptorchidism and penile hypoplasia. Although surgical correction is generally recommended in young dogs, the long-term clinical course of severe hypospadias under conservative management remains poorly documented. In this study, we describe an unusual canine case of severe perineal hypospadias that survived to geriatric age under conservative management and subsequently developed bilateral testicular tumors arising from cryptorchid testes. Despite recurrent urinary tract infections during early life, the patient maintained an acceptable quality of life with long-term supportive care, providing a rare clinical example of extended survival without surgical correction. Because no molecular material was available from the patient, publicly available mouse transcriptomic datasets related to genital tubercle development and Leydig cell differentiation were consulted only as contextual reference. These datasets illustrate established developmental regulators and steroidogenic pathways relevant to genital formation and testicular function but do not represent direct molecular findings from the reported case. This report primarily highlights the clinical course and management of severe hypospadias in a dog, while using existing transcriptomic knowledge solely to provide biological context. The findings should therefore be interpreted as descriptive and hypothesis-generating rather than as evidence of a direct mechanistic link between developmental abnormalities and endocrine tumorigenesis.