A man and a woman have been charged after an eight-year-old boy was bitten on the head by an XL bully, police say.
Officers were called to Bootle, Merseyside, just after 17:20 GMT on Saturday after a report that the dog had bitten a child.
The boy was taken to hospital with "life-changing" injuries, where he remains in a serious but stable condition, Merseyside Police said.
Officers seized the dog, which was later destroyed.
Amanda Young, 49, and Lewis Young, 30, both of Wadham Road in Bootle, have been charged with being in charge of a dog dangerously out of control and causing injury.
The pair, who are not related to the victim, have been remanded in custody to appear at Liverpool Magistrates' Court on Monday.
Officers said they had spoken to witnesses of the attack in the communal area of some flats in Wadham Road.
Det Insp 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."
The force added: "Officers attended and seized the dog - an XL Bully - which was humanely destroyed later on Saturday with the agreement of the owner."
New rules for owning American XL bully dogs have recently come into force in England and Wales, and will be implemented in Scotland later this year.
It is illegal to own one without an exemption certificate, and registered dogs must be kept on a lead and muzzled in public.
Det Insp Stratton said: "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."