An unusual presentation of osteochondrosis in the elbows and tarsi of a Friesian colt

Summary This case report describes the clinical, diagnostic imaging results and post‐mortem findings in a foal that underwent reassessment following surgical management of angular limb deformities (ALD) and acute onset of gait abnormalities. Upon presentation, the foal showed an abnormal stiff gait characterised by bilateral medial limb collapse during the stance phase. Severe bilateral effusion was observed in the elbow joints, along with firm, raised and marked deformation in the caudal tarsal region near the calcaneus. Radiographs revealed severe osteochondral lesions in both elbows and tarsi. Ultrasonographic examination of the elbow joints showed mildly echogenic, cellular, grainy effusion, which was confirmed as haemorrhage through arthrocentesis. Additionally, ultrasonography of the tarsi revealed moderate soft tissue swelling and bone callus formation surrounding the calcaneal lesions identified on radiographs. Osteochondral necrosis in this colt progressed to severe osteochondrosis dissecans (OCD) in the elbow joints and bilateral Salter‐Harris (SH) type II fractures of the calcanei in both tarsi. Given the severity of these findings and the poor prognosis, euthanasia was elected.