Treatment of a stallion for penile deviation caused by haemorrhage into the corpus cavernosum penis

Summary A 19‐year‐old Thoroughbred stallion developed severe curvature of its penis, preventing intromission, after breeding a mare. The cause of the curvature was found, during ultrasonographic examination of the penis, to be rupture of the trabeculae on the left side of the corpus cavernosum penis (CCP) between the cul de sac of the external preputial cavity and the scrotum, resulting in the formation of a seroma. Aspiration of the seroma performed 13 days after injury, with the horse anaesthetised, largely resolved the deviation. A complication of treatment was excessive belling of the glans penis during erection, which may have been the result of a temporary shunt created between the CCP and the corpora spongiosum penis (CSP) by inadvertently passing the spinal needle used to aspirate the seroma through the CSP. Excessive belling resolved after 3 weeks.