it's tough to know how to help the other dog... lots of exercise, play, keeping up a routine- some dogs just pine for a while. it's often better if they get to see the dog that has passed, but that is not always an option. Maybe some extra play days with friends' dogs?
I'm glad I was able to help explain some.. and there are a lot of misconceptions and false statements on the internet. Vets are not the best at explaining things either, unfortunately.
Good luck with everything!