He, his wife and two children, had gone to the park so the little girl could use her telescope. The dad said the dog began to circle the child before attacking her, biting off the top of one of her ears and causing injuries to her arms.
The dad, aged 40, said: "It's like every parent's worst nightmare. It is an incredibly awful thing to go through. As we were packing up to leave, a dog suddenly ran up to our family and immediately attacked, injuring my wife who was instinctively trying to protect her."
He said that the children had not approached the dog or been near it before it attack, and the first time they saw it was when it made its way towards them. The children, he says, were 'very frightened' and tried to run back to their parents.
"This was a totally unprovoked and savage attack," he said, "The dog attacked on multiple occasions and, at one point, circled my daughter and my wife in what looked like a shark attack that you would see on TV."
Despite hitting the dog 'a number of times' to try and make it let go, it continued to attack his daughter and wife.
The little girl was rushed to hospital and later transferred to a specialist unit where she will continue to be treated. Her dad said she is going to have 'major constructive surgery at another date'.
He added the events had 'totally devastated' the family and that they were all in a state of shock. he said he would like to see tighter controls on the ownership of dangerous dogs, dogs on leads and muzzled and more dog free parks.
The dog, which was not on a lead, was later destroyed. Its owner, Gary Hindley, 56, an unemployed builder of Chingford, north-east London, initially ran away from the scene but later handed himself into the police before pleading guilty to being in charge of a dog in a public place.