Armani may just have absorbed odors into his skin from the pound like what happens when you cut onions and your hands stink of it for hours. If that is what the problem is, better health, good food, detoxing, bathing...and all other the great thoughts I have seen so far...may help. I
forbade my DH (the former 'Honey Bun King') at one point to cut onions...his hands would reek of it for days and it would keep me awake all night, the stench. Now he has no problem with it, but it is because of health improvements...and no more crap food, addition into his diet of proper EFA's, etc.
Also, I use virgin coconut oil (not from copra and not hydrogenated) on my Yorkies (all my pets, actually) for minor skin irritations, scrapes, etc., and they love it so I also give it as treats. It takes very tiny amounts...and makes them temporarily a little oily. I also use it as my only skin cream/hand lotion. It is anti-viral, anti-microbial, anti-bacterial, etc. and I don't worry about them eating chemicals. I cannot promise it will help but it has been my experience that it doesn't hurt.
You definitely do not want to traumatize the poor little baby too much after all he's been through, but could also try using things known to neutralize or absorb odors...like a baking soda tub bath or vinegar solution rinse...to see if that helps. I know it sounds crazy but vinegar and tea tree oil are the only things I know of that kill mold and mildew...bleach just whitens the stain...so if he had anything microscopic on his skin or coat, those things might eliminate it completely. Even other essential oils that are puppy safe may help...maybe even lavander oil, which is very useful for lots of stuff...I doubt you'd need much. If you think it might work, but he shouldn't eat it, you might try just putting it on him for 10 minutes or so, then bathe it out. Plus you'd get to do all that nice snuggle washing.
I would definitely use a properly pH balanced conditioner after using anything either dramatically acid or base, though, so as not to dry out his skin, etc...and I'd probably rub him down with coconut oil, then bathe him again in a good doggie shampoo and conditioner.
There are also some natural herbs, like parsley and basil, and spices, like clove and peppermint, that are used for natural flea control, but also work to neutralize odors especially 'breath' in humans. I think I saw one recipe calls for boiling parsley and lemon for a few minutes and using the water as a spray...it may have been rosemary, though. If it is something puppies can eat, you could put the fresh leaves in a blender and make a powder to sprinkle on...or use a dried her from the spice rack. I have seen using parsley water on their food for parasite control, too. I believe.
These are just temporary measures I'd look into if I was facing the situation you described...until his body correct itself. You could search it...and should to make sure there is no issue for canines...I'd send the recipes to you except my storage hard drive died and I lost all that stuff.
Anyway, if you try it and it helps, you'd only have to do it until the smell goes away naturally.
I hope the lump on his neck goes away quickly, and I am sorry you have such a difficult decision to make about his leg. Good luck...so glad your Holly and Armani are together again...sending kisses and hugs to both from Brody and Mia!
