I suspect I'll be getting back to you in bits and pieces.
The hessian sack mattress - I think that's because Chloe is still a puppy and chewing and pulling and tearing is just so satisfying. I used to go through one per month - until they started lasting a year. About 4yo for the Elkhound. She's probably beginning to get that crop of teeth (they teeth until 2yo), so it could be worth handing out some 'serious' chew time stuff, like half a cow bone. Its about the only thing that 'adult' dogs seem to find irresistable, apart from garden furniture.(yes, experience, labs eat everything). I'm glad those sack thingies are cheap. I went through so many (I soon learnt not to buy the expensive ones).
I am thinking that Hudson needs a new collar - a big fat leather one, that will give him some protection. Studs are good. Think 1970's and 1980's punk rocker. I think Chloe also needs to learn that biting her buddy isn't a good thing.... So, grab some chilli oil and smear the lightest amount on the back of Hudson's neck - avoid the cuts - where she tends to grab him. Pop them outdoors and don't supervise for a few minutes
(make sure she gets the opportunity to get a mouth full of chilli). Wash Hudson's neck when you bring him back in, and also wipe his back paws, just in case he's had a scratch. It is a problem when a dog doesn't respond normally, which is what Hudson seems to be doing - he isn't yelping or anything, which means he's not telling Chloe she's OTT. So, we need to tell her (firmly) she's hurting him - and the chilli oil is a good safe means to do that. She won't enjoy it - but it won't actually harm her. Kind of like Hudson offering a nip back, IYKWIM?
I'll have a think further on the overall dynamics, as it involves teachng Chloe to be less dominant, and Hudson to be a bit more dominant. Not an easy task!