Where I currently live, terminally ill nearing their end often fall in a pattern of eating and drinking less and less, to the point of having nothing (not even water). This process of dying takes 1-2 weeks(!). Longer if some liquid is still imbibed.
This is a common ending of a terminally ill process and apparently seen as humane. Though I think if anyone treated their dog like that, we'd report them for animal abuse.
I don't have good answers to most questions surrounding this topic. But I'd like to get to a point where people are treated as humanely as their pets in their final period. And I can't even tell you the current practice isn't, just that it does not at all feel that way to me.