I repeat, my advice is to go to a veterinary neurologist, a specialist.
I went to 3 different vets and 2 specialists (veterinary dermatologists) within 1 year before I found a specialist that correctly diagnosed my dog with environmental allergies, she is now stable x 5 years.
Veterinary care has become like our human health care. If you have a serious condition you go to a specialist.
Your dog’s symptoms have absolutely nothing to do with his diet (imo). The symptoms sound neurological and would probably respond to medication.
Ps: If the symptoms are not severe, the ultrasound (to rule out certain conditions) and a Prozac trial sounds reasonable, may be worth a try.
This is not veterinary advice; consult a veterinarian.
