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Elaine, my initial thoughts are that her turning her head in that manner in conjunction with mydriatic (wide open pupils) indicates a newly blind dog or, instead, a postural repetitive myoclonus - a type of head tremor in which there is an episodic high-frequency "yes" or "no" movement of the head often confused with focal seizures. My initial exam would be a thorough look at the fundus (back) of her eyes for pathologic changes in her retinas which may or may not be present. A lesion involving structures outside of her eye (optic chiasma, e.g.) and in her brain can also cause blindness. Blood work isn't expected to be helpful in diagnosing these dogs. A thorough neurologic exam which might include MRI is indicated.
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