Surgical management of carpus valgus deformity caused by persistent ulna in three large breed foals

Summary This case series describes the occurrence of persistent ulnar remnants in three large breed foals presented with bilateral carpus valgus deformity. Distal ulnar ossification was diagnosed based on lateromedial radiographic projections. Treatment included distal ulna ostectomy in conjunction with transphyseal screw placement or periosteal stripping and medial extension shoeing. The axial deformity was corrected successfully in two foals. One foal aged 2.5 months that showed advanced stages of carpus valgus deformation as well as carpal bone crushing failed to respond to therapy. The case series highlights that carpus valgus deformity may have profound causes. In cases that fail to improve with standard management approaches, prompt recognition of a complete ulna is mandatory and surgical intervention unavoidable to successfully correct axial deformity in large breed foals.