I am blessed with a dog that trims his own nails, he has a whole process to it. He has never seriously injured himself doing so, and only cracked a nail once or twice in the last 6 years. However my parents have a dog, that really doesn't enjoy getting his nail cut at all. To the point where the vet has to do it now. Is there anyway once they've reached that much disliking to it,to get them back to being able to tolerate it?