In 2008, the BBC produced a controversial documentary on the harmful effects of pedigree dog shows. According to the documentary, many dog owners are causing dangerous levels of in-breeding; this results in dogs with crippling genetic deformities. One RSPCA vet said, "What I see in front of me is a parade of mutants. It's some freakish, garish beauty pageant."
Most of our domestic varieties have harmful problems due to mutations and the breeding required to maintain breed purity tends to amplify these problems further. The changes we see in dogs today give no support to evolutionary expectations.
After dogs originated from an ancestral wolf-type creature there genomes have undergone mutational decay. Their genomes have suffered a loss but not the creation of new information evolution needs to be believable, as a mechanism from changing microbes into mangos, mutts and mankind.