We are seeing FAR, far too many discussions in groups about whether or not to castrate male mules. This also includes donkey jacks that are going to pet homes. FIRST, no male mule should be left intact. EVER. There is zero need for him to be intact. He is sterile. He cannot breed. However, his brain (the one between his ears) doesn't know that, and his hormones will take over at some point. DO NOT LEAVE MALE MULES INTACT. They should preferably be castrated while they are still nursing, which gives them nursing on mom for support, and she will keep him moving to help with drainage and healing. Male donkeys that are not to be used for breeding should also be castrated. There is no need to keep them intact, especially if they are going in with other livestock or to be used as pets/around children. The main difference for a castration in longears vs horse is the vet must be certain to ligate (tie off) blood vessels while they are in-hand to prevent excessive bleeding.