Why is my dog shaking, panting, and cuddling suddenly for no reason?

Hello! I'm sorry to hear that Eleanor might not be feeling well. There are several things that I think of when I hear about dogs that are trembling or shaking. First, dogs that tremble and shake may be experiencing pain. Conditions like luxating patellas (kneecaps that pop out of place) and back injuries come to mind with smaller dogs like Bichons and Shih-tzus. You may not have seen the initial injury, but if they "tweak" an old or chronic injury, it can make them shake, pant, and want to be clingy, as they don't understand why they are hurting. Next, behavior changes in middle-aged dogs could be caused by metabolic disorders, like hypothyroidism or Cushing's disease. I would also expect to see other symptoms with these disorders, like weight changes and a poor hair coat, so if you see any other physical changes, this could account for Eleanor's shaking. Lastly, stress can also cause shaking and trembling behavior (like from storms or major construction going on in the neighborhood). I definitely recommend having Eleanor evaluated by a veterinarian for pain and/or other disorders before chalking her trembling up to a behavioral issue, as many conditions like pain and hypothyroidism can be managed with treatment, and she'll be much happier for it.

Good luck, and I hope that Eleanor gets better soon!