Controversy at Crufts may normally be confined to docked tails, unkempt coats and ill-timed barking, but the world’s premier dog show has found itself locked in a far more uncomfortable contretemps.

The BBC, which has had exclusive broadcasting rights to the event for more than 40 years, said yesterday it was reviewing its coverage in the light of a programme that it had commissioned on canine health.

The documentary, to be shown on BBC One at 9pm tonight, claims that the breeding process used to produce pedigree dogs has resulted in a high incidence of inherited genetic disease. It raises what the programme makers believe are serious concerns about the ethics of dog shows and their emphasis on breeding purity.

The corporation announced yesterday, 24 hours before the screening of Pedigree Dogs Exposed, that it was reviewing its coverage of Crufts. The show attracts three million viewers to the BBC, which has screened the event since 1966.

Times Archive, 1965: Changing appearance of the Basset

Queen Alexandra exhibited Bassets. Before the 1914 War there were seven packs hunting in England

• Foreign dogs

• The top dogs at Crufts

Related Links

• For pedigree breeding

• Against pedigree breeding

The documentary sets the BBC on a collision course with the Kennel Club, which runs Crufts and is the oldest all-breed club in the world, taking more than 200,000 registrations a year. The BBC is one year into a three-year contract with the club, understood to be worth several million pounds.

Two years in the making, the documentary shows many dogs suffering from genetically induced illnesses, including epilepsy, and compares practices at the 135-year-old club to Nazism in its emphasis on breed purity.

A spokesman for the club dismissed the idea as offensive, “not just to us but to the people who suffered at Hit-ler’s hands. What we are talking about is dog breeding – let’s get this into perspective.”

But the BBC fears it will not be able to defend its coverage of Crufts after the showing. A spokesman for the broadcaster said that it would be seeking a meeting to discuss “the impact of the matter raised by this film”.

Three quarters of Britain’s seven million dogs are pedigree and it is estimated that veterinary bills now amount to £10 million a week to cover what the documentary makers, backed up by evidence from the RSPCA and others, claim are increasing cases of ill health.

The programme showed a prize-winning Cavalier King Charles spaniel suffering from syringomyelia, a condition that occurs when a dog’s skull is too small for its brain.

Veterinary neurologist Clare Rusbridge says in the film: “The cavalier’s brain is like a size 10 foot shoved into a size 6 shoe – it doesn’t fit.”

It also showed boxers suffering from epilepsy, pugs with breathing problems and bulldogs who were unable to mate or give birth unassisted.

Steve Jones, Professor of Genetics at University College London, told the BBC: “People are carrying out breeding which would be first of all entirely illegal in humans and secondly is absolutely insane from the point of view of the health of the animals. In some breeds they are paying a terrible, terrible price in genetic disease.”

Selective, or line breeding, is commonplace among pedigree dogs and the Kennel Club has registered dogs bred from brother-to-sister and mother-to-son matings.

The RSPCA’s chief veterinary adviser, Mark Evans, told the BBC: “The show world is about an obsession, about beauty, and there is a ridiculous concept that that is how we should judge dogs.

“It takes no account of temperament or fitness for purpose potentially as a pet animal, and that to me makes no sense at all. It is a parade of mutants; a freakish beauty pageant.”

The Kennel Club disputed the emphasis on illness and complained that the BBC had not shown it the programme before transmission.

The club spokesman said that “90 per cent of all pure-breed dogs were healthy”, and added that the BBC had not been willing to accept that the club had made efforts to fund research into canine health. He hinted that the club would complain that the programme was not impartial.

In a statement on the club’s website, Ronnie Irving, the chairman, said that “members of the production company seemed to have preconceived and extremely biased views on the subject”.

He went on: “We have been at pains to remind the BBC of the requirement in its charter to be rigorously impartial and balanced in its reporting.”

The film-makers, led by experienced scientific documentary maker Jemima Harrison, will also have to defend themselves against any complaints that the subjects of the film were unfairly treated.

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010