A. This might be a sign of stroke or "old dog syndrome" as it is usually referred to. In many cases the symptoms will get better withing 3-4 days, in other cases it will not get better at all.
This condition doesn't have any specific treatment, only time will hopefully make a change.
Bear in mind at his age a brain tumor is a viable option as well and cannot be ruled out.
I recomend taking him to the vet in order to get him physically checked.
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