Fracture characteristics to distinguish between accidental injury and non-accidental injury in dogs.

Non-accidental injury (NAI) refers to trauma arising from deliberate physical abuse and is increasingly recognised as an important differential diagnosis in veterinary medicine. Given the sensitivity and importance of identifying NAI, clinicians, pathologists, and veterinary forensic experts need clear scientific evidence to support their diagnosis. The aim of this study was to investigate fractures occurring in accidental and NAI in dogs by comparing the radiographic features of fractures in 19 dogs with abuse fractures and 135 dogs with accidental fractures. Radiographic findings indicated that the following five features should raise the index of suspicion of and support a diagnosis of NAI: (1) the presence of multiple fractures; (2) fractures occurring on more than one region of the body (forelimb, hindlimb, or axial); (3) transverse fractures; (4) fractures presenting at a later stage of healing (delayed presentation); and (5) multiple fractures at different stages of healing. Staffordshire bull terriers were over-represented in the NAI group. Many findings in this study correlate with patterns seen in human NAI fractures. However some aspects show significant differences, serving as a reminder that veterinary forensics cannot rely on data from existing human studies.