Sad news, my father has decided to quit hunting.

[John Y Cannuck]

One of the guys I hunted with hunted from the age of 18 until he was 89 years old. He'd be hunting now, except he up and died on us. The only years he missed were the years he was over in Italy in WWII.
Keep your self in decent shape, and you can hunt a very long time. Very sorry to hear about your dad, but his health could turn around.