Very senior dog having hind end balance issues?

[Sue R]

Has anyone ever had a dog (I'm talking my old dog Celt) who would occasionally hold their tail tightly-wrapped around the hind leg, almost like they were trying to balance? And then, shortly after, would relax and go back to holding it normally? I'm wondering if Celt isn't getting a bit shakier in the hind end and this is a reaction to feeling a bit of a hind end balance problem. It's almost always to the right side but this morning, when he had the longest episode of this I've seen, he did do it to the left side just briefly after an extended time (maybe five minutes or so) of holding it to the right. It wraps tightly, just like when he's balancing for a hard turn or stop, somewhat like it is in this photo by Michelle Dobbs, but wrapped more tightly forward around his thigh.