Owners of existing XL bullies may have neuter their dogs and muzzle them in public
Restrictions will be placed on American XL bully dogs to "safely manage" them once a ban on the breed comes into force.
Owners of American XL bullies will not face a cull of their pets after Prime Minister Rishi Sunak promised to ban the breed following a spate of dog attacks.
But Downing Street said measures will be put in place to cover the "existing population" of the dogs in response to concerns that they will still be allowed on the streets once a ban on new owners comes in.
Existing owners could face a requirement to neuter their dogs and muzzle them in public, the Government's chief vet has suggested.
The Prime Minister's official spokesman said: "We will need to safely manage the existing population of these dogs. Exactly what that looks like will be a topic for the consultation.
"And there will need to be some sort of transition period."
The first step of the move to ban American XL bullies will take place this week, with police, vets and other experts helping to define the breed.
Then the consultation will take place on the ban, which will come in by the end of 2023.
Environment Secretary Therese Coffey told MPs that guidance about the enforcement of the Dangerous Dogs Act will also be tightened.
"While the courts have the power to allow people to keep banned breeds with certain conditions, like being muzzled and neutered, the number of so-called exempted dogs is higher than a decade ago," she said.
"That was not the intention of the legislation passed over 30 years ago. Therefore, we will also review our guidance to enforcers of the law."
The Chief Veterinary Officer indicated on Saturday that there will be an "amnesty" approach to American XL bullies, echoing the way the ban on pit bull terriers under the Dangerous Dogs Act was introduced in the 1990s.
Professor Christine Middlemiss said owners will need to register their American XL bully, with the dog required to be neutered and muzzled and on a lead when in public.
They will also need to be insured.
She stressed that anyone complying with the new restrictions will be able to keep their dog.
