Now I would like to point out that neither party is ideal imho as show breeders breed for looks and often ignore the original functionality of the dog entirely; while work breeders often loose sight of long term use of a dog for high drives. Now not every show dog lacks the working drive and many more breeders are becoming interested in breeding dogs to be BETTER at what they are supposed to do BUT are also keeping within the original confirmation standards of the breed. Likewise not every working dog has had conformation ignored so they all look nothing like the original breed.
Unfortunately there are far more breeders who don't care and just want a cute/pretty dog to make puppies so they can sell them.
Here are some examples of what i mean in the discrepancies between work and show bred dogs:
Dachsund
Old Style:
AKC CH today:
Border Collie
Work:
Show:
Labrador retriever
Work:
Show:
Springer Spaniel
Work:
Show:
English Setter
Work:
Show:
And of course the German Shepherd one of the most popular dogs in this debate:
Work:
Show:
Of course MANY other breeds have been hit with the show bred stick and others like the Australian Shepherd have been hit with the "can I have that dog in a smaller size please?" stick.
And then we wonder when we have these dogs that are just miniature working dogs or prettier versions why they have all these problems behaviour wise. And differences aren't always between work and show bred, some examples are purely what the dog breed has become and it isn't necessarily an improvement on the original, take the dachsund and the english bulldog.
Of course bulldogs and bully breeds in general have suffered the most and any google search will show you that most of the time the dogs have to be bred by artificial insemination and puppies delivered by c-section because of the large head. We have gone so far as to make it that this breed could barely survive on it's own. There are those though that are trying to bring back the old look by creating such breeds as the olde english bulldogge
Olde English Bulldogge
vs
English Bulldog
Other places to read on this issue: (i am not endorsing the information on these sites just presenting them as additional reading)
http://www.workingpitbull.com/amstaffpit3.html
http://www.terrierman.com/rosettestoruin.htm
http://www.greys-holt-kennels.co.uk/pugarticle.htm
http://realgsd.ca/GSDinfo/Care/Jeanm/balance.htm
http://realgsd.ca/GSDinfo/WSblood/work_show.htm
http://www.bordercollie.org/akc.html