This is a surgery done on a standing, sedated horse using local anaesthesia. It is done standing because they bleed a lot less than when under anaesthesia. It is not a sterile surgery, as it enters the nasal cavity; however the surgical site is clipped and scrubbed using an antiseptic soap. The area isn’t draped because even the most heavily sedated horse tends not to tolerate having a sheet over its head for an hour. The local anaesthetic is the same as that used by your dentist, and the surgery is comparable to having a tooth removed.