Jason Devincent, 18, who says he is homeless, pleaded guilty in DuPage County Circuit Court on Monday to owning a dog at large and not having a dog license.
The dog, Buster, got loose from a yard in the 700 block of Autumn Drive, where Devincent was staying for a few days, and bit Anthony Duffy Jr., 5, who lived on that block.
The boy suffered 4- and 6-inch wounds to the back of his head that required surgery. He was released from the hospital after a day.
The pit bull was euthanized several hours after the incident.