Police were called to a house in Atherton, near Manchester in northwest England, where they found the body and "were confronted by a number of dogs that were aggressive and out of control", a statement said.
Four of the dogs, believed to be bull mastiffs and Staffordshire bull terriers, were put down humanely by armed response officers, while the fifth was secured inside the house.
The teenager was believed to be visiting the house where she died and nobody else was present. Superintendent Mark Kenny of Greater Manchester Police offered his condolences to the teenager's family and said the incident was "extremely distressing".
"While our enquiries to find out what happened are ongoing, this girl's injuries are consistent with her having been attacked by dogs," he said in a statement. The dead dogs are being examined as part of the police investigation.