The deadline has passed for owners of XL bully dogs to apply for certificates of exemption to keep their pets before a ban on the breed comes into force.

From Thursday, it will be a criminal offence to own an XL bully in England and Wales without a certificate.

Applications had to be submitted by midday on Wednesday.

According to the RSPCA, the Government last week said 30,000 dogs had been registered, and the Department for Environment, Food and Rural Affairs (Defra) has been contacted for an updated figure.

The total number of XL bullies, estimated by animal groups, has ranged between 50,000 and 100,000, the RSPCA added.

The latest deadline follows restrictions which came into force at the end of last year which mean the dogs must be kept on a lead and muzzled in public.

Breeding, selling or abandoning the dogs also became illegal as of December 31.

Dr Samantha Gaines, dog welfare expert at the RSPCA, said there are concerns that owners will have failed to apply for certificates in time or at all.

“There’s been a lot of communication from Defra around the need to ensure that people do go through exemption but I think there will be some individuals that are not aware of the ban, and there are obviously going to be some that just decide not to take their dogs through registration either,” she told the PA news agency.

Dr Gaines said there have been reports of owners struggling to comply with the restrictions that came into force at the end of last year, particularly the requirement to muzzle their pet in public.

“In order for a dog to get used to wearing a muzzle it is really, really important that it is introduced in a very slow, gradual way… but for some dogs, they have really, really struggled with it,” she told PA.

“One of the issues has been the head shape of this type of dog, that it’s been very difficult to actually get a muzzle that will be both secure and comfortable.”

Dr Gaines told PA the Government is aware of those concerns and that Defra has been having regular meetings with members of the Dog Control Coalition – which the RSPCA is part of.

She also pointed out that owners may have financial difficulty meeting requirements that incur costs, like neutering dogs.

“What has ended up happening is that there has been significant reliance on the charity sector to step forward and help owners,” she said.

“What the RSPCA is now doing is working with the Blue Cross to actually then provide people with the means to have their dogs neutered at a subsidised cost.”

The Government move to ban the breed followed a series of attacks involving XL bullies, with one man dying after being savaged by one of the dogs last year.

But Dr Gaines said in a statement that banning the breed “is not the answer” and warned of a “huge risk” that rescue centres and vets will be unable to cope with a likely surge in demand due to the restrictions.

She said: “Instead, we want to see the UK Government commit to the enforcement and improvement of current breeding and dog control regulations, and to promoting responsible dog ownership and training.

“Improving the way dogs are bred, controlled and treated throughout their lives is key to preventing dog bite incidents.”

Dr Gaines called breed-specific legislation “outdated” and insisted the RSPCA will continue to campaign against legislation that “unfairly punishes dogs based on their appearance”.

“The ban on XL bullies not only remains devastating for so many dogs, but is also taking a heavy toll on owners, on rescue centre staff who have grown close to dogs in their care, and to veterinary teams who face the prospect of being asked to put to sleep healthy dogs whose behaviour poses no risk,” she continued.

“There is a huge risk that rescue centres and the veterinary profession will not be able to cope with the demands put on them by this law.”

Scott Fryer, policy manager at Battersea Dogs and Cats Home, told PA breed bans do not work effectively, citing that dog bite incidents have increased by 188% in the last 20 years.

“We have an issue with breeding. The breeding system can be made better, so that effectively we’re breeding for welfare, not just for certain looks or things like that,” he said.

“It’s not a quick one answer, unfortunately, it is a systematic change,” Mr Fryer added.

To qualify for an exemption certificate, owners must prove their XL bully has been neutered by June 30.

If they have a pup which is less than a year old on Wednesday, they must be neutered by the end of 2024, and evidence that they have done so must be provided.

A confirmation of neutering form must be submitted by those dates, according to whichever deadline applies for the dog in question.

As well as neutering their animals, XL bully owners seeking an exemption must also pay an application fee, hold third party public liability insurance for their pets, and ensure the dogs are microchipped.

Owners of XL bully dogs in Scotland will also be subject at a later date to the safeguards after the Scottish Government replicated legislation in place south of the border.

The dogs were added to the Dangerous Dogs Act on October 31 last year, giving owners two months to prepare for the first stage of restrictions.

People with dangerously out of control dogs can be jailed for up to 14 years and banned from owning animals, and their pets can be put down.