The boy was inside a home on Riverdale Ave. near Georgia Ave. in East New York when the dogs attacked him at about 6:45 p.m., officials said.
"All of his left face was gone. He couldn't breathe. I pressed a towel to his face but there was nothing left," the witness said.
Medics rushed the boy to Brookdale University Hospital, but he was later transferred to Long Island Jewish Hospital, police said.
Emergency workers took two dogs out of the building.