Here is a gallery of pictures that I have found, to give you an idea of what goes on.......
Puppy Farm Tails
exposing the suffering of dogs.
Here is a video for you all to understand how these poor dogs really live, although this video is based on American "puppy mills", it is the same and happens all over the place, this video is VERY graphic......
This web site contains a list of some pet shops that "buy in dogs" to re-sell as well as some useful info......Pet Shops
bravenet.com