Ultrasonographic assessment of the atlanto-occipital space in healthy Thoroughbred foals and Thoroughbred foals with neonatal maladjustment syndrome.

Ultrasonography of the atlanto-occipital (AO) space may be useful as a non-invasive diagnostic tool in neonatal foals. The aims of the study were establish a range of values for ultrasonographic measurements of the AO space in healthy Thoroughbred foals and to compare these variables in healthy foals with foals diagnosed with neonatal maladjustment syndrome (NMS). Ultrasonography of the AO space was performed on 38 healthy Thoroughbred foals and 28 Thoroughbred foals with NMS≤4days of age. Transverse image spinal cord height (P=0.001), width (P<0.001) and spinal cord cross sectional area (P<0.001), and longitudinal image dorsoventral diameter of the ventral spinal artery, were significantly smaller in foals with NMS than in healthy foals. Ratios of spinal canal to cord width and cross sectional area were significantly smaller in healthy foals than in foals with NMS (P<0.001). Spinal canal variables were not significantly different between groups. Several ultrasonographic measurements of the AO space were significantly different between healthy foals and foals with NMS. Further investigation is warranted to investigate the clinical application of this technique.

Necrosis of the femoral condyles in a four-week-old foal: clinical, imaging and histopathological features.

A 4-week-old Thoroughbred filly foal with a history of sepsis was evaluated for right hindlimb lameness. Bilateral femoropatellar and femorotibial joint effusions were detected. Ultrasonography and radiography of the right stifle revealed signs of joint collapse and periarticular swelling. Computed tomography revealed abnormalities in the bone density of the medial femoral condyle of the right hindlimb and lateral femoral condyle of the left hindlimb. Euthanasia was recommended based on the severity of the lesions. Gross and microscopic examinations revealed extensive separation of the articular-epiphyseal cartilage complex from the subchondral bone of the femoral condyles. The histological features suggest an ischaemic aetiology; comparisons are made with lesions of osteochondrosis and avascular necrosis of bone.