Dog owners: how do you say goodbye?

How do I say goodbye to a great friend, my dog Tilly, 13 years old? She is getting worse day by day, and yet continues to hang in there. The past year has been very tough for her, and in the past 48 hours she has relapsed with vestibular dog syndrome.

I realize that in humans, people sometimes hang in there, beyond any medical explanation, to say that final goodbye, or reunite with that estranged loved one. In fact, sometimes doctors encourage family members to tell their loved one that’s it’s ok to die.

So I guess my question is, how do I let her know it’s ok to die—and as a dog owner, has this happened to you?