Penile Fractures in Young Bulls Raised in Feedlots in Southern Brazil

Background: Penile fracture is a pathology of young cattle that perform precocious and disordered breeding. The incompatibility of height between males and females and sodomy between males cause a great pressure on the sigmoid flexure and retractor muscle of the penis, which are the main causes and sites of organ injury. This study aimed to describe the epidemiological and pathological aspects of penile fractures observed in young bulls raised in pre-export feedlots (PEFs) in southern Brazil.Cases: In 2 PEFs located in the municipalities of Pelotas (property 1) and Capão do Leão (property 2), 3 male cattle [1 from property 1 and 2 from property 2] presented edema of the foreskin and perineum, associated with dysuria. The evolution of the clinical picture was approximately 20 days in all cases, with evolution to death. The bovine necropsied on property 1 had an increased volume and inguinal edema, involving the penis and scrotal sac. Necrosis of the subcutaneous tissue and local musculature was also observed. The testicles were surrounded by the necrotic tissue, and the right testis was swollen, with flaccid parenchyma adhering to the tunica albuginea. In the necropsy of 1 bull from property 2, an increase in the inguinal volume was observed, with an extensive area of necrosis and edema extending from the prepuce to the caudal musculature of the scrotal sac. There were also marked varicosis in the sigmoid flexure and necrosis of the adjacent region, without the involvement of the corpus cavernosum. During the necropsy of the 2 young bulls, fragments of organs from the abdominal, thoracic, and brain cavities were collected and fixed in 10% buffered formalin. From the bull of the property 2, an anatomical piece consisting of the penis, prepuce, and testicles was also collected and fixed in 10% buffered formalin. After 48 h, the tissue samples were cleaved, embedded in paraffin, cut into 3-µm-thick sections, and stained using hematoxylin and eosin (HE). A histological evaluation of the penile lesions in both cattle revealed intense hemorrhage, congestion, and necrosis of the muscles and tissues adjacent to the corpus cavernosum. In addition to areas of dystrophic calcification, neutrophil and macrophage infiltration was also observed. In the bull from the property 1, an intense edema and proliferation of fibrous tissue surrounding the urethra were noted. There were also marked tubular degeneration and intense infiltration of neutrophils, lymphocytes, and macro