XL bully owners have spoken of how their dogs are “gentle giants” with “beautiful temperaments” on the eve of it becoming a criminal offence to own the breed in England and Wales without a certificate.

A mother-of-four from Sheffield said her one-year-old male XL bully named Theo is “part of the family”, while another owner of two XL bullies in North Yorkshire said the new legislation to ban the dogs without an exemption has “affected me massively”.

The deadline for owners of XL bully dogs to apply for certificates of exemption passed on Wednesday at midday, however there are concerns that owners will have failed to apply for certificates in time or at all.

Kerry Heath, a 37-year-old childminder, said she has done “everything we can” to ensure she can keep her XL bully Theo, who lives “happily” alongside her four cats and two smaller dogs.

“He is the most gentle giant you will ever meet,” Ms Heath told the PA news agency.

“I’m a childminder and all the children absolutely love him, the parents love him, they’re always asking to stroke him.

“We’re complying with all the restrictions and we’ve done everything we can to ensure we can keep him because he’s part of the family.”

Ms Heath said the attitude around her XL bully dog has changed as new restrictions have been put in place, including wearing a muzzle and being kept on a lead.

She said prior to her dog wearing a muzzle, passers-by would stop to stroke him and say “how beautiful he was” – and on December 31, when wearing a muzzle became a legal requirement for the breed, “people avoided him”.

“They crossed the road, they pulled children away,” she said.

“It makes me feel so sad because he was so loved by other people before.”

Ms Heath added that the ban is “devastating” for owners who may not be able to afford the exemption certificate or who missed the deadline.

“There’s loads (of dogs) in rescue centres that aren’t going to get a home now because it’s against the law,” she said.

“I know there have been some horrendous attacks but I think this breed of dog can be just as loyal as any other dog if they’re brought up in the right way and trained from being a pup, as we’ve done with Theo.”

XL bully owner Charl, 30, who did not wish to share her surname, told PA that the new legislation to ban the dogs without an exemption has “affected me massively”.

The home carer has applied for exemptions for her two-year-old male XL bully named Thor with a “beautiful temperament” and for a female XL bully puppy named Lily that she is adopting, she said.

“Everybody that knows [Thor] loves him,” she said.

“Obviously, he’s intimidating-looking so other people are weird about him, but anyone that knows him and has met him absolutely adores him.

“It’s been so difficult because people were funny about him before the ban, but now people are crossing the street, they’re dragging their dogs away from him and it’s just not needed because he’s friendly.”

She decided to adopt another XL bully “because I know that so many dogs are going get killed and so many people have given them up”, she said.

“Lily was already born before the ban and she can’t leave her mother until she’s eight weeks old so I paid for her and exempted her before the ban.”

She added: “I wouldn’t agree with any dog being banned because I genuinely believe that no dog is bad.

“It’s not the dogs, it’s the people that are owning them and doing whatever they are doing to the dogs.”