A single bite from his family's nine-year-old pet dog - so gentle it barely woofed at a stranger - nearly killed three-year-old Charlie Stirton last year when the boy climbed on the sleeping animal's back to ride it "like a horse".

One bite by the startled dog caused traumatic lacerations to Charlie's face, nose, eyelids, forehead and scalp. A CT scan of his face and skull revealed that the 50 kilogram dog's jaws had fractured Charlie's fragile skull and broken his nose. He was lucky to avoid permanent brain damage, doctors said.

Charlie Stirton, now 4, with his younger sister Isla. Charlie nearly died when his family dog - never aggressive before - bit him once when the young boy climbed on its back. Stirton family

Pet dogs - owned by a child's family, relative or close friends - are responsible for

84 per cent of dog bites, a new study has found. Another 8 per cent of children were bitten by a neighbour's dogs, meaning only 8 per cent were bitten by a stranger's dog, the Royal Australasian College of Surgeons Congress in Sydney heard last week.

Susan O'Mahony, James Cockburn and colleagues at Brisbane's Lady Cilento Children's Hospital found doctors had treated 426 children for dog bites since the end of 2014. Of the 151 treated in the past year, a third required hospitalisation for at least a night, often with extensive rounds of reconstructive plastic surgery.

"We are seeing a huge number of, particularly, small children, under 10 - and we presume the same is happening in every state - with significantly life-changing, traumatic injuries as a result of dog bites," said Dr O'Mahony, the surgeon who treated Charlie.

A 3D image of Charlie's skull after he was bitten by a dog. Supplied

Of those children seen at the hospital, about half were under four years of age. And about 70 per cent had been bitten on the face.

About one in three households in Australia owns a dog. A review of admissions to public hospitals from 2001 to 2013 found dog bites were a largely "unrecognised and growing public health problem", with as many as 26 bites per 100,000 population among children aged zero to four.

Surgeons say dog bites are under-reported. A study in Perth last year found a surprisingly large number of children had been bitten on the face. Another review of hospital admissions in Geelong, Victoria, by Dr Jackie Tran found similar results, but also that adults bitten by dogs often delayed seeking help until infection set in, which then often required one- to two-day stays.

Bites represent a huge proportion of the children's hospital workload and a massive cost to the health system, Dr O'Mahony said.

She urged families to anticipate situations that could trigger bites such as a new child or a small child poking an older dog.

"Even the 'best' family dog has potential [to bite], and put in the wrong situation it happens, and too regularly for us," Dr O'Mahony said.

"No matter how familiar the dog is, and even if it is understood to be a friendly dog - something I hear all the time - if that dog is even accidentally woken up with a sudden start, or accidentally poked in the eye, or pulled on the ear, or given a fright, their natural instinct is to snap, and they go for the face because that's what they do to each other," she said.

Michael Stirton, Charlie's father, said his son owed his life to doctors at Lady Cilento hospital.

The bite was "really out of character" for the dog, said Mr Stirton, who lives on a property between Brisbane and Toowoomba. "The biggest contributing factor was that the dog was asleep and an older dog."

Charlie and his younger sister Isla had been taught to treat dogs with respect, and never to poke, pull or climb on them.

The bite caused traumatic lacerations to Charlie's face, nose, eyelids, forehead and scalp Supplied

Mr Stirton stressed that Charlie had not been mauled - it was a single bite from a dog that had never shown any signs of aggression. The dog was put down after Charlie was bitten last September.

Fresh out of hospital, Charlie would tell anyone who asked that he had been hurt saving his Isla from a crocodile.

The force of a crocodile's bite is about 10 times more powerful, but a 50 kilogram dog has the same bite strength as a tiger.

"[Dogs] are designed to eat bones, so if a dog has a wide enough bite, and it can grab the child in the upper part of the head, it can absolutely penetrate bone," Dr O'Mahony said.

While large dogs' jaws exert more power, Dr O'Mahony said any dog can cause life-changing facial injuries. "We've had loads of nose and mouth injuries from small dogs," she said.

After a scan of Charlie's skull and face, which revealed extensive injuries, Dr O'Mahony and Dr Cockburn urged doctors to check for "intracranial injury" (traumatic brain injury).

Dog bites - and the scarring they cause - had such a huge psychological impact (equivalent to the trauma after a car accident) that the hospital now has a full-time staff member providing counselling and support. These bites often cause distressing disputes and guilt in family and friends.

Mr Stirton is now outspoken about separating small children from dogs - particularly those that are large or aggressive. Recently he urged a friend to get rid of a dog. "I said, 'Mate, trust me, you will never forgive yourself if it leaves your daughter with a scar for the rest of her life'."