An estimated 10,000 XL bully dogs have not been registered as a ban on the breed comes into force, police have warned.
As of midnight on Wednesday, it is a criminal offence to own one of the dogs in England and Wales without a certificate.
Owners will also have to follow a strict set of rules around their care including having them neutered, keeping them on a lead and muzzling them in public.
As the deadline passed, around 40,000 people had complied with the new legislation and had formally registered their animals with the Department for Food and Rural Affairs.
But the National Police Chiefs’ Council warned there could still be as many as 10,000 rogue XL bullies that have not been checked and certified.
Unregistered dogs risk being destroyed
Assistant Chief Constable Mark Hobrough, who is the NPCC lead on dangerous dogs, said those who had chosen to ignore the rules ran the risk of going to prison and having their pet seized and destroyed.
He said: “This type of dog in the wrong hands is a very dangerous thing and unfortunately we have seen this type of dog connected to some undesirable ownership.”
He went on “We are incredibly grateful to all the dog owners who have registered their dogs on the database.
“It is important for the wider community when they see these types of dogs out in their community if they are adhering to the law, if they are muzzled, on a lead and are held by a person over the age of 16.
“My urge to the community would be if you see these types of dogs within the community that weren’t adhering to these aspects of the law to report them by 101 or, obviously if there is an incident involving one of these dogs involving an attack or aggression, that would be a 999 response.”
He urged anyone who had not registered their XL bully to still come forward so the appropriate checks could be carried out to ensure the dog did not pose a risk to the public.
He explained: “If dogs are reported to us, there would be a proportionate response.
“Police would attend to check out the dog and it would ultimately lead to warrants being issued for dog seizures.
“It would then be up to the courts to decide on the fate of the dog but it could end up being destroyed.
“People in possession of such dogs without being on the register run the strong possibility of having a fine, a conviction and potentially imprisonment.”
23 killed by dog attacks since 2021
The new legislation was brought into force after a series of attacks, some of them fractal, involving the XL bully breed.
Up until 2021, there were on average three fatal dog attacks a year but since 2021 a total of 23 people have been killed as a result of dog attacks, with many linked to the XL bully breed.
In September last year, a 52-year-old man from Staffordshire was killed by one of the dogs as he tried to protect his elderly mother.
In the wake of that attack Rishi Sunak, the Prime Minister, moved to ban them, adding the XL bully to four other breeds named in the dangerous dogs act, including the pit bull terrier, the Japanese Tosa, the Dogo Argentino and the Fila Brasileiro.
Commenting on the new legislation, Steve Barclay, the Environment Secretary, said: “The ban on XL bullies is now in place meaning it is illegal to own one of these dogs unless it has been registered.
“We have delivered our pledge to bring in this important measure to protect public safety, and we expect all XL bully owners to comply with the strict conditions.”