Does he have any allergies???
Maybe he is allergic to the ingredients in the chews? Only reason I ask is because my dog also has idiopathic head tremors, which I have been keeping track of them, and he only gets the head tremors when he is going thru a allergy flare?
that’s the only time my dog gets a head tremor is from a allergy flare.
I’m not saying allergies is the issue, every dog is different and some dogs get them for no known reason, but I would keep track of when he gets them and what he has had recently.
I always try to get it to end, by saying ‘where is your toy’ and he looks at me and it stops.
Green lipped mussel powder( I use Thrive brand-if your in Canada), and it’s a great preventative and maintenance, one of my other dogs has severe arthritis and she shows no signs of arthritis cause of the green lipped mussels(it’s a whole food source which is much better absorbed than just added synthetic).