Every dog's different. My own dog, a 60-lb Shep/Sighthound mix, has spent more than a few nights in my Marmot Peapod tent with me, and often with another human camper for a cozy three. Condensation's never been an issue, and when one of us humans is having gastrointestinal issues with certain protein bars, we can always blame it on her.

My only bear encounter while camping had her so scared, she was more concerned about scooting underneath me than anything. (weird, since she's actually encountered bear scent other occasions with no such reaction). But to be safe, I keep her leashed while in the tent and, 90% of the time, while on the trail. The latter can be dangerous, especially when scrambling, but I've taught her the command "wait", so she doesn't drag me up or down technical stuff. If I'm overly concerned, that's when I unleash her.

I use a pack made by WolfPacks. Never overload your dog...but with the right fit and conditioning, your dog should be able to carry his/her supplies for a weekend getaway (barring canned food, of course).

Make sure you have a good canine first aid kit/guidebook, as well as contact info appropriate for away-from-home trips, both in the dog's pack and on its collar (my dog is also chipped).

Booties are also a good idea if you're going to be crossing rough terrain, or on a longer trek than the dog might be used to. They can also help prevent tearing of your tent and sleeping bag/pad.

Oh, yeah--pack a fleece blanket and/or camping chamois towel for your dog to lay on in your tent, and a tick removing tool.