At the start of 2016, the FBI announced that it would start tracking animal cruelty in the same way it tracks felonies, such as arson, burglary, assault, and homicide. Oftentimes, the agency said, crimes against animals are indicators of further criminal activity.

But how does one know if a pet’s injuries are naturally occurring or caused intentionally by a human?

Tufts University and the American Society for the Prevention of Cruelty to Animals are attempting to define the differences between the two. In a study slated for publication in the Journal of Forensic Sciences, the researchers performed a comparative analysis between animal injuries caused by motor vehicle accidents (MVA) and those from non-accidental injuries (NAI).

“Clinicians still face many difficulties in identifying animal abuse,” the researchers wrote in their study. “Animals are unable to speak for themselves, and some animals’ innate personality and trust will even belie the cruelty they have suffered. Additionally, the actual cause of the injury often differs from the description provided by the client.”

In the study, 426 dogs and cats with MVA injuries were compared against 50 dogs and cats with NAI. The 426 cases were provided by the Foster Hospital for Small Animals, which operates at the university’s Cummings School of Veterinary Medicine. The 50 other cases, deemed criminal cases of abuse, were provided by the American Society for the Prevention of Cruelty to Animals’ Humane Law Enforcement Division.  

“Injuries significantly associated with MVA were pelvic fractures, pneumothorax, pulmonary contusion, abrasions, and degloving wounds,” according to the researchers. “Injuries associated with NAI were fractures of the skull, teeth, vertebrae, and ribs, scleral hemorrhage, damage to claws, and evidence of older fractures.”

Additionally, abused animals tended to have rib fractures on both sides of the body, whereas rib fractures from MVAs usually appeared on one side of the body.   

Establishing these patterns, according to the researchers, will help clinicians differentiate between causes of trauma.

“This study contributes to the expanding body of research in the growing field of veterinary forensic medicine and will help forensic veterinarians continue to give a voice to the voiceless,” said Robert Reisman, of the American Society for the Prevention of the Cruelty to Animals, in a statement.