My father has alzheim and he don't want to eat he can walk no more how long that he still have is this is the last stage please ?

Yes. : Based on what you are providing, my suggestion is to have your father's primary care physician refer him to a multidisciplinary team to address late stage Alzheimer's -- if his primary care physician has not done so already.

Possible: Patients in late stages of Alzheimer's may behave like this. Sometimes acute conditions, namely infections might contribute to poor intake. They are usually accompanied by other symptoms that are extremely hard to discern in demented individuals. If in doubt take your father to his physician.