Police who responded to the house in Wigan found Jade Anderson unconscious, The Daily Telegraph reported. Four dogs were shot dead and a fifth was described as "contained."
Police said the dead dogs appeared to be two Staffordshire bull terriers and two bull mastiffs. They belonged to Beverly Concannon, mother of the friend Jade was visiting.
Superintendent Mark Kenny of Greater Manchester Police said Jade's injuries were "consistent" with a dog attack.
"Jade was eating a meat pie when one of the dogs jumped up to try to snatch the pie. Jade moved it away from her mouth and the dog went for her throat," a friend said. "At least two of the other dogs joined in and started biting her legs."
The friend said Jade, a student at a Manchester high school, was a "very timid shy person."