I am in no way suggesting you have your highly domesticated dog run around a city grabbing all the available live vermin it can get its paws on!
I am fortunate, I do have a small garden (fully fenced/safe) where my dog will eat in the warmer months. When it rains or it's cold, he will eat in the kitchen. The kitchen floor is easy to clean.
By an appropriate, healthy raw dog diet - I am taking about raw meaty bones - chicken wings, not live rats! My dog is fed approximately 60% raw meaty bones (whole chicken wings, portioned rabbit, salmon, raw egg sometimes with shell etc.) plus approx 10% offal and the rest is some mushed up raw veggies to which I normally add a little ACV and kelp.
Sounds expensive .. a little more yes, but no vet bills!
When he eats indoors, I will cut the meaty bone pieces into smaller chunks. Outdoors, he likes to thrash his meat around.
For your information, I would never put my dog on a chain - I agree, that is cruel. I also do not let my dog roam freely unless just in the garden and house - anyway, there are strict rules against that in the UK.
There is no reason to rearrange your dogs life - It is the same with humans. Even those following MH's formula for health will not be living outdoors like a cave man, almost naked but covered by a furry loin cloth!
All you need do is to add the right type of raw (but dead) food as detailed above and in the links previously provided .. to ensure your dog gets the type of food his digestive system requires. No need to bring home live rats I promise! That type of diet will ensure a dog gets all the nutrients it needs to get well and stay well.
Oh .. as I recall in your earlier post about calcified stones. Why do you suppose stones get calcified? Calcium is the most alkaline mineral of all .. and it goes to the areas where the body is most toxic. The calcium is trying to neutralise the toxicity. Now .. where do you think your dog got his calcium if he is eating a commercial diet? Well .. it's not from his diet!! .. the calcium is being pulled out of his bones to go to the most toxic place to help him. Survival. so, calcified stones are not excess calcium in the body ... but the body using its calcium reserves from the bones to go to a place of toxicity to help neutralise acids.
If your dog were to eat raw, meaty bones, such as good quality chicken wings, there will be plenty of calcium and minerals in the bones. This will help to rebuild, restore and heal. bones are essential for the mineralisation of dogs.
There are many posters on the pets forum who have had their older dogs convert to a healthy diet and the dogs have thrived, healed and got better. It's never too late to teach an old dog a new trick :-)
It's the same for humans .. even the old can receive healing once they remove what creates toxicity and add what heals.