Poor soul, sad to hear that. The numbers are indeed really high, but I think fluid IV is worth a shot. I think it’s better to get a third opinion on this as well - show his reports to another vet before coming to a conclusion and then go with the safest option. Has your vet ever treated a dog or a pet with a similar condition? How long has your dog faced this issue? I wouldn’t come to a conclusion yet, try to find an animal clinic who specializes in these cases. Some websites are there that can help you with - greatvet, vetstreet etc. You can find others also if you look online with details of the vet etc to make your decision. Take care.It is indeed a stressful time when a loved one gets sick.
He is doing well, bless him. He hasn't got very long, but he is still enjoying things. So I would say -why not try it? It is impossible to cure him of course. But it is a good palliative treatment wich might give him some more happy days.
There would be no harm in trying the diet, but he might not like it. If he doesn't, I would say -let him eat anything sensible for dogs that he has an appetite for at this stage.
We always think "human table food" is terribly bad for dogs, but depending of course on what....it isn't necessarily. Meat and fish (especially if it's a bit without added seasoning or sauces....and steamed vegetables ....potatoes and pasta, quinoa, brown and white rice, even a little brown bread are all perfectly fine for dogs! No harm in a few "fries" even, within reason.
Anything he can eat which doesn't upset him, is safe for dogs, and he is happy to eat sounds like it would be good.
I am sorry, because I don't have personal experience with late stage kidney failure, but I send my kind thoughts to you and your dog, bless him.