Well....I was glad to read your "rant", barbrex. Because a dog never is "just a dog" and anyone who says that has never loved a dog.
And not all vets and people who work in vets' offices are any good! It does sound like your vet has it right though, but I can imagine you don't get much help from the others. It was similar at my vet's place. One young junior vet was surprised when I couldn't get a big square-edged pill down my dog. It was hard and bitter and she kept spitting it out and I couldn't disguise it in food.
I asked if they had a liquid option for the medicine (a paracetamol pain killer) She suggested Calpol which is a childrens' painkiller which you can buy at any store. Okay, so I read the ingredients list....and would you guess? There were things in there which are definitely toxic for dogs! Not for children, but for dogs -yes!!
Our main vet (the head of the place) would not have suggested that. I trusted him. But that young girl did not know enough.
So I do know how uncaring some people in the vet's office can be. You have to watch out for them.
Anyway, I think it's great you made some home cooking which your dog loved. Yes you can keep him going and find some nice suitable food that he will like. There are some good recipes for home cooked dog meals. Adding a supplement (vitamin/mineral/Omega 3 etc) will be a good idea. I think nutritional supplements for dogs can be bought online. Have you tried looking for something like that on Amazon? It may just come in one pill, which you may be able to crush to add to his food...
Dogs do like fish also. Some people think they don't. But they do, and it is good for them too. It is also good for the heart. So maybe he might like something like salmon and broccoli with brown rice or potato?
No one can probably tell you how long he literaly has left. But so long as there is some good quality of life that's what counts.
And no, a dog is never just a dog. They are our dearest friends and family members and sometimes sole companions, and we love them very much!
Yes Salmon and other oily fish is very good because of the Omega 3 oils, which are good for the heart. But a dog shouldn't have fish at every meal. Maybe about 2-3 times a week is okay.
Lean meat is also okay. Rabbit is actually good lean protein, but many butchers don't supply it any more, and buying it opens a can of worms about "farmed rabbits" (which is a very cruel business.)
In the old days wild rabbits used to be shot and passed away instantly. There used to be stores and small butcher's shops which sold them -and Pheasant. But not so any more! Venison (deer meat) is also good for dogs. All game meats should be stewed slowly to make sure they are tender.
They are very lean meats very good for dogs.
Otherwise, chicken breast is a good idea, or lean thigh meat. Lean Turkey meat is also okay. Just watch it for the fatty bits and skin etc, as that can be too fatty.
Vegetables are good, and carbs are OK as a proportion of the diet. Quinoa is also very good for dogs and contains good protein (though they shouldn't be fed this as a meat subsitute, as it is basically a seed.)
Quinoa is very nice. I like it!
Seafood like Prawns are fine. But again, not the major part of the diet, but an additon now and again. Many stores sell frozen Prawns in packs you can keep in the freezer. They thaw very quickly.
You can even include fruits like apple and blueberries. Dogs can happily eat fruit as an additional treat, and the vitamin C and fiber is good for the heart too. Apple seeds are toxic, but the fruit and peel is very good for dogs! They will also help with constipation issues.