K. Pieber, A. Kuebber-Heiss † , P. Kuebber ‡ and J. Kofler Equine Veterinary Education February 2010 22 2 62 - 65 This case study describes a rare case of a fibro-osseous tumour in the distal part of the fourth metacarpal bone of a 13-year-old horse. The tumour was surgically removed and wound healing occurred without complications. A specific diagnosis was reached by considering the clinical and histological features of the mass. However, the process was complicated by the different classification systems for this type of tumour. When classified according to the veterinary literature, ossifying fibroma is the appropriate diagnosis, whereas in human medicine this term has been replaced.