We finally found the right medications for my 10-year old loyal potato (she's had low thyroid function, immune system trouble caused by the low thyroid function, a rattlesnake bite on the nose, arthritis, and so on) -- she's now acting half her age and happily jumping on rocks to pose for treats, and it's so nice to share her story with the vet.
Everyone at the vet visibly brightens up when they interact with a happy well behaved dog.