The program says an emphasis on appearance over robust health in Britain has led to growing health problems for pedigree dogs ranging from epilepsy to reproductive issues.

"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," said University of London genetic professor Steven Jones. "In some breeds they are paying a terrible price in genetic disease."

The BBC said that one extreme example is the pug. There are about 10,000 of the little dogs in Britain, but genetically there are fewer than 50 distinct individuals.