The boy was due to undergo surgery on Monday
A woman has been bailed after questioning by police after an 11-year-old boy's ear was torn off in an attack by a pit bull-type terrier.
Officers are carrying out further investigations into the incident in Alway, Newport, south Wales.
The boy has also had to undergo surgery to repair damaged nerves in his left arm after the attack last Wednesday.
Gwent Police said the 40-year-old woman has been arrested on suspicion of possessing or keeping a dangerous dog.
A spokeswoman for the force said she had been released on police bail pending further enquiries.
The dog has already been destroyed.
Paramedics took the boy to the Royal Gwent Hospital in Newport, and he was later transferred to Morriston Hospital in Swansea, where the Welsh centre for burns and plastic surgery is based.