I am SO VERY SORRY to hear this. It was just one year ago that we had to do the same with our Samoyed, Hobbes. It's never easy to lose a member of your family, whether they walk on two legs or four... just know that he's not in pain anymore and your Aunt did the right thing.
I'm sure that, somewhere, your beloved J.D. is playing and romping with my Hobbie... like puppies do when they're healthy and happy and pain-free. My sincere sympathy to you and your family for you loss. My thoughts are with you!!
~~Wiccan~~