Claudia--thank you for the advice. I just ordered the Medizyme. I'm encouraged that you say what I'm seeing is normal for an aging hound; I've never had a hound live to nearly 13. My oldest hound was our Beatrice, who was healthy as a horse at 12, when she developed hemangiosarcoma.
Rhemus is so, so thin, though--I'm actually embarrassed to post a pic. Think Quilty, though. His breathing is what worries me the most. I think he's using most of the calories he eats just to keep breathing. Sometimes, like now, he is breathing quietly. But mostly, he seems to struggle. He was checked for LP, and it's not that.
All I know is I'm not ready to let him go. Someone suggested starting him on prednisone via pm; I'm hoping that that will give him some more time and will talk about that with the vet on Monday.
If anyone else can think of anything, or anything I should bring up with the vet, please let me know.
And, prayers for my boy, please.