It is sad, but it doesn't hurt the dog in any way, and it doesn't shorten their life span, so that's good. I've been noticing it for several months now. Katy's are mild at this point, it started when she would lay down, then I started seeing this slight tremor once in awhile, the up and down tremor nod. Now I'm seeing them every time she lays down, and I'm seeing them when she's standing, and she can kind of loose her balance and act like she might sit back and fall down. They only happen for a few seconds.
Just wondering, cause IHT can mimic epilepsy as well. Haven't looked up canine epilepsy yet....