Post-operative care
After surgery, a protective bandage was placed and changed every three to five days. The horse received procaine benzylpenicilline (22.000 u/kg bwt, i.v., q. 8 h) for five days and acepromazine (0.02 mg/kg bwt, per os, q. 6 h) during the first ten days after surgery. Sixteen days after surgery, skin sutures were removed and post-operative radiographs were taken (Fig 3 ). The limb was kept bandaged until full wound healing was obtained. Three weeks later, the horse became painful at manipulation of the scar and a small exudative wound appeared. After radiographic and ultrasonographic evaluation, two bone sequestra were identified at the level of the fistula. The sequesters were followed up radiographically and the fistula was rinsed daily and kept under bandage. Six weeks later, the sequesters were still visible on radiographs but because of the clinical improvement and decreased drainage from the fistula, they were left in place to resorb. The first chemotherapy was planned four weeks later and was administered standing, while the horse was sedated with detomidine (15 µg/kg bwt, i.v.) and morphine (0.01 mg/kg bwt, i.v.). Regional anaesthesia consisted of subcutaneous infiltration of wound edges with 20 ml of lidocaine. Afterwards, 5 ml of a 10% carboplatin solution in an equal volume of sesame oil was injected at the level of the bone defect. A protective bandage was placed for another three days and no further medical treatment was needed. After bandage removal, training was gradually built up. Initially, the horse was hand walked for short periods each day. Once the fistula had closed, additional rehab included aqua training twice a week. Eventually the aqua training was reduced to once a week and replaced by regular training until the horse reached its normal level of work. Control radiographs were taken every six months. The periosteal reaction of the second and third metacarpal bone remained stable and the radiolucent zones became more delineated (Fig 4) . Additionally, some trabecular sclerosis could be observed. The horse was sound for the next three years and was used for recreative riding.