If you have to put one dog down, should you bring the other dog to the vet to say goodbye? Is that normal or okay to do?
I honestly wouldn't recommend that, for the reasons warpus and Lemon Merchant mention.
At home, they will be surrounded by familiar things, familiar smells, familiar sounds... your remaining dog will probably be upset afterward for awhile, though, wondering where his/her friend is. There will be a grieving process for both of you.
Maddy was worried about Chloe before I took her to be euthanized, but she knew Chloe was extremely sick. And after I returned home without Chloe, Maddy was out of sorts... this happened in the middle of my moving situation back in March, and Maddy had to adjust to both the loss of her lifelong friend
and moving to a new place (even though it was just one floor down and one suite over, it was still new).
This is still affecting her. She's been so used to having another cat around to play with, and they used to groom each other all the time. I give her lots of attention and play with her, but it's not the same kind that another cat can give.
This is going to be a very difficult time for all of you, and in my experience it's best to worry about one pet at a time. When it comes to the actual euthanasia, will you be there with your dog when it's done? If so, that means you can focus on your own goodbyes with your dog, without worrying about your other dog.
Please accept a

from a friend who's been in your shoes recently. I can barely see my screen right now...
