Seven adults and a child were sleeping when the fire broke out around 1:30 a.m. Wednesday on the 1200 block of South Garnsey Street.
The smoke detectors went off but no one heard them. The dog started barking and woke everybody up.
"She started barking and barking, which woke up one of my sons. By the time we got up, the whole house was full of black smoke," said resident Vera Mendez. "If it hadn't been because of her, I don't know what could have, what would have, happened."
It took 40 firefighters about 30 minutes to knock down the flames. The cause is still under investigation.