My little boy

This is Bill, he's 15 years old and has been our family dog for about 3 and a half years. Now he's slowly passing away, it's 3 days he refuses every food and water, does not walk anymore, if not for to change position for sleep. I go chech on him every hour or more so (he with the other dog have a shed outside the house) and now I'm going to sleep fearing again of not finding him in the morning. He really liked being in the open countryside and in the house with us for company. At the very least he's not alone, when we're not around with him there's Scooby (the other dog seen in the photos). I post some of the best photos of him so that anyone could maybe appreciate him.