How can I help my grieving schnauzer Ollie?

by Bronwen
(Santa Fe, NM - USA)

Ollie had Duff and Duff had Ollie. Two mini black schnauzer litter mates.
Altho we were advised that because of a congenital heart condition, Duff would most likely not make it to two, he made it to 13.
As he began to decline Ollie was always at his side.
They did everything together for 13 years.
It has been three months since Duff has passed and Ollie is clearly grieving.
He has stopped calling his call for Duff when he is awake but still does so in his sleep. We take him for adventures, drives and walks and love him up and fix his favorite foods.
What else can we
do and what should we know about a devoted senior schnauzer boy?
What should we be doing to help him and keep him as healthy as possible. He has some hip problems and has lost some hearing but other than that he is a healthy senior.
Thanks.
Bronwen