You need to be aware and understand that since the dane is a large breed, you MUST NOT let it get excessive exercise, we breed Newfoundlanders occasionally, and we recently had a problem with a customer where they didn't listen to us, and worked their 5 month old Newf, letting her romp in the snow, and run behind his ATV...unfortunately this can cause joint, and bone problems. Typically, you shouldn't exercise a large breed excessively (as mentioned above, running, chasing, romping in snow, etc.) until after 1-2 years of age, 2 being the best. Also, you should make sure that the parents have a clean bill of health and show no signs of hip displaysia, of course this doesn't mean that your puppy would never develop hip displaysia, but at least it means you did your research, hip displaysia is common in larger breeds, but to be honest i've only ever known one dog in my life who's had it, so if you exercise the puppy conservatively, you may even be able to prevent it.