My friend's 12 lb dog has paralysis in both eyes, where she is unable to close them, in addition to perpetual bobbling horizontally, where she is unable to control them. This started in one eye, then the next day was in both. Her MRI was unremarkable, and her test for both lyme disease and encephalitis was negative. They really are at a loss. The doctor prescribed an antibiotic as a precaution and now they are simply waiting. Are they overlooking anything here? How should they proceed?
The eyes are moving back and forth horizontally and the lids cannot close is that correct? or are the eyes moving up and down?
This sounds like facial paralysis. You can read about that here
http://www.provet.co.uk/health/diseases/facialparalysis.htm
It can be due to an inner ear infection, a neck problem, a tick disease which you ruled out, hypothyroidism, and inflammation in the area of the nerve.
The eyes moving back and forth goes with vestibular disease which you can read about here
http://marvistavet.com/html/body_vestibular_disease.html
As this may be due to an autoimmune issue sometimes using a steroid like prednisone may help. You can ask your vet about that possibility.
If the eyes cannot close you may want to keep them lubricated if they are drying out and your vet can suggest an eye ointment to help with that.
Scroll down to info on facial paralysis on this page for more info on things to check
http://neuro.vetmed.ufl.edu/neuro/P_Nerves/P_nerv.htm
and more info here that suggests long term antibiotic treatment may resolve this if the problem is an inner ear infection
http://www.vetspecialists.co.uk/06_Animal_Welfare/Neurology_Facts/Facial_Paralysis.html
Hope this helps you!
Experience: 30+ yrs dog home vet care & nursing, rescue, behavior&training, responsible show breeding, genetics