the bull dog was bred to take down bulls and other big animals in battle by the romans.... In the u.s during the civil war they were used to bite horses legs to take generals off of there horses. In europe in the late 1800's people were having problems with rats, terriers were good at finding and killing them, but they were not powerful. They bred the bull dog and terrier and when they perfected the breed thats where we got our modern Pitbull. A pitbull in europe in the early 1900s killed 2000+ rats in 2 minutes.