Merseyside Police say the family of the 17-month-old victim are “absolutely devastated”.
A 17-month-old girl has died after being attacked by a dog in her home in St Helens, police have said.
The girl died in hospital after the attack in Bidston Avenue, Blackbrook, at around 15:50 GMT.
Merseyside Police said her family were “absolutely devastated” by her death and had only bought the dog a week ago.
The dog was killed by police. Officers will carry out tests to see if it was an illegal breed, as well as trying to identify its previous owners.
Det Insp Lisa Milligan said: “This is a tragic incident and our thoughts are with the child’s family at this devastating time.”
She added: “Whilst we are in the very early stages of the investigation into this extremely tragic incident we can confirm that the dog was only bought by the family a week ago.”
Anyone who witnessed anything in the area round the time of the attack, or who has information about the dog, is asked to contact the police.