Tom Chambers of Wendouree was walking his daughter's four-year-old dog Tilly along Gregory Street this morning when they were set upon by what he believed were two large Staffordshire Terrier cross-breeds.

Attacking his dog, which was on a leash, Mr Chambers said the two terriers picked her up and threw her around like a rag doll, piercing her neck and tearing a large chunk out the side of her body.

Tilly managed to escape and run home, with the pair of dogs hot on her tail, while Mr Chambers sustained bites to his hand and leg, requiring hospital treatment.

Police were called to the incident and were soon able to locate the child, while both dogs were seized by City of Ballarat rangers.

"What really concerned me was when I saw the little girl nearby, I didn't know where the dogs had come from," Mr Chambers said.

"It was a completely unprovoked attacked. I believe these dogs should be banned, especially when you see them do something like that."

After running home and being found by Mr Chambers' wife, Lorraine, Tilly was rushed to the Wendouree Clinic of the Ballarat Veterinary Practice.

With much of the skin torn off her torso, Dr Richard Lawrence and nurses performed the life-saving two-hour operation to reattach the skin and conduct internal observations.

"It was probably one of the worst dog attacks I've seen," Dr Lawrence said.

"The amount of skin that got torn off was disturbing, but you can see that quite often with Whippets.

"The teeth has gone through the muscle under the ribs but they are very resilient dogs and she is doing quite well."

Dr Lawrence said it was likely Tilly would have to undergo further operations, but remained hopeful she would make a full recovery, despite some significant scarring.

City of Ballarat general manager city infrastructure Eric Braslis said the dogs had been seized and were being held in the pound while an investigation was conducted.