Re the wet and muddy dog issue:
My dog's pack contains a couple of Handi-Wipes which I use to towel him off at bedtime. They remove most of the mud and make him a little less sopping. I then put on him a sweater I made out of an old lightweight polypro base layer shirt of mine. This puts a buffer between his wet fur and my sleeping bag yet allows him to dry during the night. With the polypro sweater and the DWR of my sleeping bag shell, this appears to be sufficient to protect my bag. I also don't let him roam around getting muddy after we've set up camp.
I discovered that even though my dog is mostly Lab, he starts shivering on really cold nights (even if not wet). That's because at home he's an indoor dog. The polypro "sweater" plus his pad (1/8" GG Thinlite) keeps him warm enough when it's below freezing. If it's a relatively warm night and dry, I don't use the sweater–overheating is always a problem with Labs.
If it's a dry night, I spend a few minutes combing the dog at bedtime. This procedure removes dust, dried mud, excess dog hair (my dog sheds perpetually) and any ticks that might be crawling around. (The ticks will die, thanks to Frontline, once they've bitten, but they may spend an hour or more lookinhg for the best place to latch on.) He loves this procedure, too.