In 2009, the Children’s Hospital of Philadelphia released a five-year review of dog-bite injuries. The review states that 51 percent of attacks were made by pit bulls.
In 2009, another study was published by the American Journal of Forensic Medicine and Pathology. The study ran for 15 years and it has concluded that pit bulls, German Shepherds, and Rottweilers are among the most common breeds that cause fatal dog attacks in Kentucky State.
In 2011, the Annals of Surgery published a study, which concluded that Pitbull attacks lead to more expensive hospital bills, higher risk of death, and higher morbidity rates compared to other breeds of dogs.