Thoracic trauma in newborn foals

In a report describing life ending fractures (255 horses) from the Livestoc k Disease Diagnostic Center, Kentucky (1993 and 1994), 32 foals had rib fra ctures. The purpose of our study was to examine the incidence of rib fractu res in newborn foals on a Thoroughbred studfarm by physical and radiographi c examination, to determine factors which may contribute to the problem and to document any clinical consequences. All foals (263) included were exami ned within 3 days of birth. The thoracic cage was palpated externally for a bnormalities and all foals were placed in dorsal recumbency to evaluate tho racic cage symmetry. Radiographs were used to diagnose foals with thoracic cage asymmetry (TCA) and rib fracture (RF). A diagnosis of costochondral di slocation (CD) was made when no radiographic evidence of fracture was prese nt but there was severe TCA, Fifty-five foals (20.1%) had TCA (9 RF), One t o 5 ribs were fractured on 9 of 40 radiographic studies. No consequences of the thoracic trauma was detected clinically, radiographically or ultrasono graphically in this group of foals or at a 2- and 4-week follow-up examinat ion. The percentage of foals with a history of abnormal parturition was hig her in the TCA foals (15%) compared to the normal foals (6.8%). There were more primiparous dams in the TCA group than in the normal foal group. Filli es (56.6%) had a higher incidence of birth trauma than colts (43.4%), This study demonstrates that thoracic trauma is often present in newborn foals a nd may not always be of clinical significance. Dystocia foals and foals fro m primiparous mares should be considered high risk for thoracic trauma.