First, keep your dog's claws cut short. I trim my dog's claws twice a month. Frequent trimming makes the "quick" recede more so you can cut them a little shorter each time.

Second, if you haven't already, crate train your dog. Use plenty of rewards and keep the crate times short at first. Your dog will soon regard his crate as a place of security. It's also the best place to leave your dog when you have to go somewhere for a few hours--you can be sure your house and its contents will still be intact when you return! This training will transfer to the tent--my dog regards my tent as HIS (!) crate, so he settles down and stays quiet.

I do make every effort to keep my dog's feet off my air mattress and my expensive down sleeping bag, but I don't worry about the tent floor (there's always duct tape). Even for the two years I had a SMD Lunar Solo with the lightweight floor (30D silnylon), I never had any holes from the dog's claws. (Ask phat--he bought the tent from me and is still finding dog hairs in it!)

I don't suggest going away from the tent with the dog inside; once he realizes you're not there, he is liable to panic and start clawing--most likely through the netting door!

Searching (see the sticky post at the top of the "General Discussion" section) will find lots of past posts on backpacking with dogs. Most, of course, with cute puppy pictures!