Four-year-old Alice Stones was killed by her family pet, police officers have confirmed.
Thames Valley police said an investigation was under way but they believe it was a “tragic, isolated incident”.
Officers and medical personnel were called to a house in the Broadlands area of Netherfield at around 5pm on Tuesday but the girl died at the scene.
The dog was put down humanely after the attack “to ensure public safety”.
No one else was hurt and there have been no arrests. The family are being supported by specially trained officers.
The breed of the dog is still unknown and remains part of their investigation.
Superintendent Marc Tarbit, Local Policing Area Commander for Milton Keynes, said: “Our thoughts are with the family and friends of the girl who has died in this extremely tragic incident.
He said the attack “has shocked the whole city” and that the investigation “continues at pace”.
“There has been wide spread speculation about the incident which is not helpful and is distressing for the family, who have asked for their privacy to be respected at this difficult time,” he said.
Local people left flowers and poignant notes at the scene today as the end-of-terrace house remained cordoned off.
A forensic tent had been set up in the garden with officers patrolling the scene.
A neighbour, Rita Matthews, 36, said she often saw Alice while walking her own daughter to school.
“She was always holding her mummy’s hand on the way back.
“It’s so sad we’re not going to see the girl again and I pray all the best to her mum to get her strength back,” she said.
She said Alice was a “happy little girl, very happy”.
“She would say ‘Bye, auntie’, and I would say ‘Bye, little girl’.”
During Prime Minister’s Questions, Rishi Sunak sent his condolences to the young girl’s family and the community in Milton Keynes.
A vigil will be held this evening in the locality. Donna Fuller, a ward councillor for Woughton Community Council, said: “It will send a strong message to the family that we are thinking of them.”
