At times, pit bulls come into the rescue after they have been mistreated by their owners, typically because they were no longer beneficial as a fighting dog. This animal is likely one of those dogs, and he seemed to have some aggressive tendencies when the video first starts rolling. What you are about to see happen, however, is certain to make your heart melt.
Most animals will respond well to a calm, smooth voice and a loving hand. It may take a little bit of trust on the part of the human but once the dog reacts to the attention, you usually see that they fall in love for the first time.