My father-in-law has Parkinson’s and he has recently has a drastic drop in his appetite, does this mean he is near death?

Hey there Inky,
he's still walking and using his walker so in my humble opinion I think that he's got some time because in end stage he more than likely will be bedridden.
I am not a medical professional but have been present for the end stage of my mom, may she rest in peace, from Dementia and another friend some years back.
The fact that he is walking is huge.
I know it's trite to say 'Hang in there' but to all of you: Your husband, your father in law and you: Hang in there. I personally know how hard this is. you have my respect.
lovbob

From what I've read, many terminally ill patients eat less and less or refuse to eat at the end. I don't think that means that everyone with decreased appetite is in end stage. The fact that your husband still helps himself to Ensure doesn't quite jibe with the picture with picture of the patient who turns his head to avoid the spoon of food being offered.

How recently was your husband seen by his doctor? I can't remember -- has depression been considered?

It may or it may suggest the need for an anti-depressant.