A new standard has been imposed by the Kennel Club because of pressure to prevent the practice of breeding unhealthy characteristics into dogs.
Since the 2008 BBC documentary Pedigree Dogs Exposed, it has changed the breed standards of all registered breeds.
Kennel Club secretary Caroline Kisko said: "This is not a closed door. Breeders have until June to come forward with reasonable arguments and we will consider them.
"Everything we have done was based on advice from veterinary surgeons."
Owner of Kezia Bulldogs Vicky Collins-Nattrass, of Birchwood, Lincoln, said: "The Kennel Club has been under extreme pressure from the RSPCA.
"We agreed with 19 changes because we could see the point of them health-wise."
Breeders say some changes will do nothing for the health of the dogs, but will make them look like boxers, not bulldogs.
Mrs Collins-Nattrass said: "We love our dogs and want them healthy, but we don't want them to be changed beyond recognition.
"Not a day goes by that you don't see a bulldog on television. It is a British icon."
The changes include reducing the size of the bulldog's head and eliminating the jowl-like skin around the face.
Registered breeders argue this will not affect "back-street" breeders, who do not have to conform with the regulations.
"They should have compulsory health checks on everyone who wants to breed, not just voluntary ones on registered breeders," said Mrs Collins-Nattrass.
For more on the arguments for and against changing the face of the British bulldog, see Friday's Echo.