We've got an 8 month old female Great Dane. We wrestled with whether or not to crop her ears, as Dane ears are freakin' HUGE if not cropped... Decided to do it, but I don't know that I'd do it again on another Dane used as a house dog like ours. It was torture watching her go through the pain of healing up and dealing with her ears being taped up like that.
We also discussed, since she was just a house dog, having her tail docked when we first got her. Obviously this isn't part of the Dane breed standard, but if you've ever been whipped by a full-size Dane's tail when he/she is in "full excitement mode", or seen what kind of damage they can do, you'd understand. Ultimately, we kept the tail, which at its base now at only 8 months old is about as big around as my wrist.
That tail can clean a coffee table off with one fell swoop, or lift our 1 1/2 year old boy off the ground and displace him about 2 or 3 feet from where he was standing, in the wrong circumstances. Luckily, he's a pretty rough-and-tumble sort of kid, and normally finds it humorous when he gets knocked for a loop by it.
It's funny to see our 5 year old lead the Dane over to the couch, where the 1 1/2 year old will be waiting to climb on her back and ride her like a horse. The dog LOVES this probably more than the kids, and when each ride ends in the inevitable crash to the floor by the 1 1/2 year old boy, I think she laughs just as much as the kids do judging by the way she acts...
Now go turn me in to child services for allowing this sort of behavior to happen regularly in my house. LOL!