UPDATE: The owner of two dogs euthanised after mauling a nine-year-old boy says she has never had any problems with the dogs.
Ambulance crews were called to a Cooper Street home in Mandurah this morning to treat the youngster for head, leg and arm injuries.
He was taken to Princess Margaret Hospital for Children in Perth after initially being taken to the nearby Peel Health Campus.
It is understood he remains in a stable condition.
The boy's 29-year-old mother and grandmother, 50, also were treated for lacerations.
The grandmother suffered an injury to her arm when she went to help the boy.
The owner of the female mastiff-cross and male American bulldog surrendered the pets to authorities and the animals were euthanised, a spokeswoman for the City of Mandurah said.
The owner, who did not want to be named, said the three injured people were her relatives.
They were at the house minding her children while she was out.
It is understood the children were playing in the backyard when the incident happened just after 11am.
“I’m in shock,” she said.
“There was blood everywhere.”
The woman said she had owned the dogs since they were puppies and they had never been violent before.
“You can ask our other neighbours - we’ve never had any trouble with them,” she said.
Both the dogs were registered and were not restricted breeds.
Police and local rangers also attended the property this morning.