Brison Aldridge was playing in a yard near his home in Manor when the pit bull mix escaped from a nearby house.
Video shows the dog chase the 7-year-old and attack him as he tries to run away.
The dog's owner raced after the animal and eventually pulled it off of him.
RELATED: Stray dog bites 5 students during recess at YES Prep campus
The boy suffered numerous bites and scratches to his legs and back.
He was taken to the hospital where he was treated and released.
The dog's owner surrendered it for testing and a mandatory quarantine.