The girl, her parents and their 11-month old baby were visiting friends but there are conflicting reports of how the attack occurred.
Local newspaper La Voix du Nord quotes veterinarian Dr Blanquaert as saying, "The dog was sitting on the sofa while people around him were making lots of noise and causing him agitation. When the little girl went to give him a kiss the animal would have felt under attack and he defended himself."
The father of the girl disagrees. "There was no party," he told the newspaper. "We were just having a coffee. The dog was on the sofa and my daughter was sitting on the floor. When she lifted her arm, the dog attacked."
Since the incident, it has emerged that the dog was already known to police. In September last year, it ate part of its owner after he died suddenly. The dog was left alone with the undiscovered body for over two weeks.
The bull terrier was taken to an animal refuge and then adopted recently by a couple who claim they did not know about its history. "We were told he wasn't dangerous and that he liked being cuddled," they told TV channel i-Télé. The animal refuge claims to have made them aware of the dog's history.
The dog will now be put down, at the request of its owners. Two official complaints have been made and an inquiry has been opened into whether correct procedures were followed concerning the adoption of the dog.