Hypospadias in a newborn puppy

A 9-hour-old labrador and golden retriever cross puppy presented with an inability to urinate normally and a congenital malformation of the penis and urethra, and was euthanased on welfare grounds. On gross postmortem examination, running 3 mm caudal to the cranial prepuce and extending to the perineum was a 3.5 cm segmental incomplete fusion of the prepuce and absence of the penis, leaving a 3 mm wide gap. A focal urethral orifice of 1 mm diameter was located at the perineum (Figure 1). These findings are compatible with a diagnosis of perineal hypospadias with incomplete preputial fusion and penile agenesis. Hypospadias is a congenital malformation in which the urethra opens ventrally to its normal anatomical location, and can be further classified as glandular, coronal, penile, scrotal or perineal, depending on where the urethra is found in these cases. Often this is accompanied by incomplete fusion of the prepuce and the shortening or absence of the penis, as seen in this case. Genetic/breed and environmental aetiologies for hypospadias have been hypothesised in dogs, but have not yet been fully established.1 Catherine Ennett and Marta Pereira performed the postmortem examination. Catherine Ennett captured the images and drafted the manuscript. Marta Pereira co-drafted the manuscript. The authors declare they have no conflicts of interest. The postmortem examination was performed as a routine diagnostic case, and no further funding was received. This case was presented to the University of Nottingham Veterinary Pathology diagnostic service for postmortem examination after euthanasia on welfare grounds. The owner has consented in writing to the postmortem examination and to the use of the postmortem findings in this publication. This image (Figure 1) shows the external genitalia on gross postmortem examination of a newborn puppy after euthanasia on welfare grounds due to abnormal urination. What is the most likely diagnosis? 1) Urethrorectal fistula 2) Hypospadias 3) Anorchism 4) Paraphimosis 2) Hypospadias.