The Flagler County Sheriff's Office says 41-year-old James Irvine of Palm Coast was arrested early Saturday.
The Daytona Beach News-Journal reports the child's mother called police after learning Irvine left the baby alone while he went out to drink. She was at work at the time.
A police report says he told her the "pit bull was watching the baby." The child was in his bedroom with the door shut when she came home. A deputy reported the dog was sitting outside the room.
It's not known whether Irvine has an attorney.