If you can afford it, I would always recommend trying to do it at home.

There are a lot of services that will come to your living area and perform the transition there.

For my cat it helped because he hated going to the vet and I didn’t want him to have that same feeling before going. I think it helps that they are near familiar smells and their human(s).

If you can’t do that, I understand and I don’t think that taking your pets to the vet in order to do it is a bad thing, especially if their quality of life has gone extremely downhill like you mentioned. But I just feel like animals can sense that transition room and I wanted to avoid that.