A. A part from the options that my colleague gave to you, I would like to add that head tilt and loss of balance could be commonly compatible with a vestibular disease.
Vestibular abnormalities are diseases (most likely a stroke) that could affect that part of the nervous system in charge of the balance (which is located on the base of the brain). There are some diseases that can predispose to strokes such as hypertension due to chronic renal failure or hyperthyroidism. Coagulation abnormalities can be affected as well.
I would as well strongly recommend to have her checked by your veterinarian. Blood test and urine analysis, together with blood pressure measurement will help to have a better clinical picture.
A. This is either a severe internal ear infection or a brain tumor. take her to the vet, as it can be treated if it's an ear infection. if it's not, a tumor will not be treatable and she will eventually get worse.
22 years old is an amazing age though, good for her!
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