Testicular torsion in foals and stallions

Summary Testicular torsion is a rare condition in horses characterised by a change in the position of the testis due to the testicular mesentery twisting around its own axis; it can occur both when the testis is still in the abdominal cavity and when it has descended into the scrotum. Depending on the degree of rotation, this can lead to circulatory disturbances with vascular insult, ischaemia or haemorrhagic infarction. Torsion of an intra‐abdominal testicle can ultimately result in testicular atrophy or testicular regression and even clinical monorchism. Torsion of the scrotal testis may be accompanied by clinically significant local pain and colic symptoms. Torsion of the abdominal testis is often only detected incidentally during a cryptorchidectomy. In addition to primary testicular torsion, secondary testicular torsion resulting from an increase in testicular volume is of particular significance in the case of the abdominal testis.