We do dew claw removals all the time at the shelter. It's easiest on the dog if it's done when they are a few days old, but we often have them removed when the dog is neutered. Chum had his removed as an adult. They weren't connected at all. He just needed a local anasethetic and someone with treats to distract him from what the vet was doing!

They are almost always removed on sled dogs as the claws can get ripped off in deep snow. yuk!