An attack this weekend on a young girl and two men by an American bully dog has reignited debate over whether the breed should be banned in the UK.

The largest type, the American bully XL, can weigh more than nine stone (60kg) and are strong enough to overpower an adult.

This weekend’s incident was the latest involving the breed and they have been involved in several fatal attacks.

Home Secretary Suella Braverman is now calling for the dog to be outlawed, and said on Sunday that she had taken urgent advice on the matter.

Owners, however, insist that despite their fearsome appearance and build, the dogs make loveable household pets.

American bullies are said to have originated in the US in the late 1980s, when American pit bull terriers and American Staffordshire terriers were crossed.

They have been crossed with other breeds to create an even more muscular dog.

The United Kennel Club in the US says that an American bully “makes an excellent family dog”.

“Despite its powerful appearance their demeanour is gentle and friendly,” it says, but also notes that “dog aggression is characteristic of this breed”.

There are four variations: standard, pocket, classic and XL.

The American bully is regarded as a specific breed in the US.

However it is not recognised as such by the main British dog associations, such as the Kennel Club.

Bully Watch, a group of London-based policy experts, told BBC News the breed first appeared in the UK “around 2014 or 2015”, and that numbers grew rapidly during the pandemic.

“Lots of people started buying with the intention of breeding,” a spokesperson said. “There’s models of co-ownership where you get the dog for free but the dealer gets to breed from it.”

American bullies have been involved in several high-profile attacks.

In April, a 65-year-old grandmother was killed after she tried to break up a fight between her two American bullies at her home in Liverpool. The coroner noted that she had been found with “catastrophic injuries”.

Last year a 17-month-old toddler was mauled to death in her own home by one of the dogs in St Helens, just a week after her family had bought it.

And in 2021, 10-year-old Jack Lis died from severe neck and head injuries after he was attacked by an American bully XL in Caerphilly. His mother, Emma Whitfield, has called for the dogs to be banned.

Richard Baker, an NHS consultant surgeon, told BBC News that because the dog has “such powerful jaws, the wounds are worse compared to other breeds”.

“In [American bullies] its a crushing or a tearing injury,” he said. “Once they grip they don’t let go. That kind of injury is more damaging than smaller dogs.”

He said that American bullies break bones, shred skin and damage nerves.

“If the nerves are damaged and can’t be repaired – which is often the case if its ripped out – it is common to form a source of ongoing pain,” he said.

A study published by in the Public Health journal showed there was a sudden spike in deaths from dog attacks last year – 10, compared to an average of three in previous years.

Bully Watch says its data collected from press reports shows the breed is linked to 14 deaths since 2021. The BBC has not independently verified that figure.

“We’ve documented some pretty brutal attacks,” a spokesperson said. “The majority of people should not own this dog.”

But other experts say it is wrong to use such data to draw conclusions about a single breed.

John Tulloch of the University of Liverpool has spent years studying various sources to try to build an accurate picture of dog attacks in the UK.

He told the BBC that one thing was certain: the number of attacks are increasing, but not because there were more dogs.

A BBC investigation in March, drawn from police reports, found that there had been a 34% increase in dog attacks since 2018. Over the same period, the number of dogs in the UK was estimated to have risen by 15%.

“There is something more going on than just there being more dogs,” he said. “The growth in dog bites is faster than the growth in the dog population.”

Trying to understand what was behind the rise is not straightforward.

One fundamental issue is that the words “bite” and “attack” are used interchangeably but can describe very different incidents, ranging from deaths to an injury that requires a couple of stitches.

Another is that there is no precise record of the number of dogs in the UK or their breeds, only estimates. Meanwhile, not all attacks are reported.

Dr Tulloch said: “We don’t know the makeup of those millions of dogs that are in the UK, or what the regional differences are.

“So, for example, in Liverpool, where we’ve got a really big problem with dog bites, the makeup of the dogs in the city is probably very different to, say, Cornwall.”

“But fundamentally, we don’t have that information to be able to say one way or the other what the situation is.”

No expert spoken to by the BBC disputed that the American bully is increasing in popularity.

Anecdotal evidence meanwhile suggests that they are favoured by criminal gangs because of their strength and intimidating features.

A BBC Panorama undercover investigation explored the link between organised crime and their breeding earlier this year.

Ian Muttitt, a chief inspector with the RSPCA’s Special Operations Unit, said at the time organised crime had become increasingly involved in extreme dog breeding trade over the past five years.

He told the BBC that sales in themselves were lucrative, and can also be used to launder money.

In written evidence to a Parliamentary inquiry, the National Police Chiefs’ Council said oversized dogs continue to be used as “status symbols” among criminals.

Four breeds have been banned under the Dangerous Dogs Act 1991: the American pit bull terrier, the Japanese tosa, the Dogo Argentinos and the Fila Brazileiro.

The bill gives the government the power to ban any breed appearing “to be bred for fighting or to have the characteristics of a type bred for that purpose”.

On Sunday, Ms Braverman tweeted that she was taking urgent advice on whether she could add the American bully to that list.

But because the breed is not specifically recognised by the Kennel Club, banning it under existing legislation could prove challenging.

The breed is extremely difficult to explicitly define. Some fear that to outlaw the American bully would inadvertently outlaw a range of other dogs.

The Dog Control Coalition – which includes Battersea, Blue Cross, the Dogs Trust, BVA, the Scottish SPCA, the Kennel Club and Hope Rescue – told the BBC that breed-specific bans had been proven to be ineffective.

“Thirty-two years of the Dangerous Dogs Act, which has focused on banning specific types, has coincided with a troubling increase in dog bites and fatalities,” it said in a statement. “This approach simply isn’t working.”

Some owners insist the breed is no more dangerous than any other dog.

Charlotte Towner said of her American bully XL Coco: “She’s just the sloppiest, dopiest dog I’ve ever owned. She’s great with other people, her only downside is she gets excited when she sees people.”

However, Mr Baker, the NHS consultant surgeon who has dealt with the aftermath of dog attacks, has a different view.

“I can’t see any reason why a responsible person would want to own a dog that is bred for violence,” he said. “Nobody needs a vicious, dangerous animal.”

Additional reporting by Sean Seddon