You say "valued". Which means in the 25 years he has been with you he was a valuable asset.
He has made you money and been loyal . Loyalty is a 2 way street ... Sometimes you have to invest in good people ...
We had a guy that ran into some hard times in life , my boss took this loyal employee and put him out on disability. Paid the diffence in his check that he lost being on disability . On one stipulation ... He had to get the professional help he needed ... That guy has been back and better then ever for 2 years now..
But the biggest problem was convicting him he had a problem........
My boss is a real class act, not many like him anymore.