I asked my vet that same question a couple years back.

I am a lab lover, and some pups I've rescued had their dew claws and some had them removed.

My vet said Its very common to remove the dew claws on hunting dogs. It keeps them from getting snagged or caught and then torn off, very painful for the dog.

My vet claims to has lost his hearing due to a dog that had a torn dew claw.

That makes sense! Thanks. Now I have to wonder how my little pup lost her dew claws. The breeder must have cut them off himself because I know they never took the puppies to a vet.

Most breeders remove dewclaws when pups are less than 3 days old. Their nervous system is not well developed and the procedure is relatively painless. Tail docks are generally done at the same time. Ear crops are done later, usually by a vet.

Personally I think these acts, De clawing, tail docking, ECT are cruel, Nature intended them for some reason, otherwise the creature wouldn't have them. Depending on what you alter on a dog or cat you could be removing the basic defenses, ways of talking to others of its species, or subjecting it to infection or pain.

Then again there are SOME things we as responsible pet owners MUST remove on a pet such as reproductive organs.