An eight-year-old boy is in hospital after being bitten in the head by a suspected American XL bully, police have said.
The youngster is in a “stable but serious condition” after the attack in Bootle, Liverpool area, around 5.20pm on Saturday.
The two were taken to custody after their arrest on suspicion of being in charge of a dog dangerously out of control and causing injury.
Detective inspector Gary Stratton, from Merseyside Police, said: "I want to reassure people that [the boy] is receiving the best possible care and treatment for his injuries, which are described as life-changing."
American bullies have over the years been involved in several deadly attacks.
An NHS consultant surgeon, Richard Baker, told BBC News they have “such powerful jaws” that “the wounds are worse compared to other breeds”.
He said: “In [American bullies] it’s a crushing or a tearing injury. Once they grip, they don’t let go. That kind of injury is more damaging than smaller dogs.”
The government has made it a criminal offence to own, breed or sell an American XL bully dog unless you have an exemption certificate. Despite the new ruling, it has been reported that some 22,420 American XL Bully dogs will not be euthanised as part of the crackdown on the breed.
Police have warned illegal XL bully owners should comply with officers if their dog is seized because their behaviour may influence a court’s decision to have it put down.
DI Stratton added: "We have seized the dog and extensive efforts are underway to establish exactly what happened.
"This case highlights in the starkest terms the potential dangers of dogs, and I would appeal to anyone with information about dangerous dogs in their area to contact us so that we can take pro-active action."