Our Shellie died a couple of years ago at age 16, but she was a larger (and really old) terrier. It was tough. Our first indication that she was starting to decline was when we realized she lost her hearing. We had to learn to use hand commands, although she was quick to pick it up. We also had to walk up and touch her whenever we wanted her attention. There were a lot of other things that happened physically to Shellie before she died, but losing her hearing was the first big step.
I just realized tonight that our Brodie has also largely lost his hearing. At first I thought (just like with Shellie) that he was being a stubborn terrier at times because he was ignoring me when I called. We did a little test tonight and really the only thing he hears is when I whistle. He is getting hand commands already which is good.
This guy was a surprise birthday gift to me on a "big" birthday and he's very special. Don't ask my husband how special he is, because you will probably get a very mixed response at best.
He sleeps a lot too which isn't all bad because we know he's not getting into trouble in the next room. But turn on that barbecue grill and he dances around like a puppy.
I think Brodie may still have several good years before his run is over, but for tonight, its a little sad knowing we are beginning the last stage of his life.