Lots of dogs which are specially bred for their looks are living in pain, according to a special investigation.
Researchers for a BBC programme found the ways some dogs are bred can cause the creatures serious health problems.
They found pugs who couldn't breathe properly, spaniels with brains too big for their skulls and boxers suffering from fits.
The group who run pedigree dog shows say most dogs are healthy and they're trying to improve the situation.
The programme, Pedigree Dogs Exposed, says dogs suffering from illnesses passed down through families of the same breed are not stopped from competing in dog shows and have gone on to win 'best in breed', even thought they're not very healthy.
The RSPCA's top vet, Mark Evans, says breeding dogs for show is wrong.
He said: "The welfare and quality of life of many pedigree dogs is seriously compromised by established breeding practices for appearance, driven primarily by the rules and requirements of competitive dog showing and pedigree dog registration."
But Caroline Kisko, a spokesperson for the Kennel Club where pedigree dogs are registered by owners, said the club was working hard to help improve the health of pedigree dogs.
She said: "Any dog may be shown but it is up to the judge to decide if it fits the breed standard."