A recent television programme on the BBC exposed the harsh realities of today's pedigree breeds. The breed specifications which are set by the Kennel Club need changing to stop such extreme and unhealthy dogs from being bred.
For example, according to the Kennel Club, the Rhodesian Ridgeback is supposed to have the characteristic ridge on their back which gives them their name, however one in ten Rhodesians are born without it, many puppies being culled for having no ridge, the ironic part being that the ridge is actually caused by a deformation of the spine, so the ridgeless ones are actually healthier.
See the following BBC page for more information:
http://www.bbc.co.uk/pressoffice/pressreleases/stories/2008/08_august/19/dogs.shtml