INCIDENCE AND DEVELOPMENT OF UNUNITED PROXIMOPLANTAR TUBEROSITY OF THE PROXIMAL PHALANX IN STANDARDBRED TROTTERS

Radiographic examination of all four metatarso- and metacarpophalangeal joints was performed on 753 Standardbred yearlings. Ununited proximoplantar tuberosity of the proximal phalanx was seen in 18 (2.4%) of the horses. All ununited tuberosities were in the pelvic limb. The condition was seen laterally in 16 horses while one horse had the medial and lateral tuberosities affected and another only the medial tuberosity. Upon follow-up examination it was apparent that 12 ununited proximoplantar tuberosities in 11 horses had united to the proximal phalanx after 6–12 months. A worsening of the condition was seen in 4 horses, and one horse had unchanged radiographic findings after 7 months. Lameness had not been observed in any horse prior to the first examination.