Our springer started behaving very oddly about a year before she died and we guessed it was a stroke. She would track obliquely across the lawn or room on her way to you and her balance seemed all wrong.
I contacted a close friend who is highly qualified vet attatched to Cambridge University and he explained that dogs very rarely suffer from strokes as we understand them.
Nearly all the problems that we see in old dogs, and assume to be the effects of a stroke, are infact mainly specific canine ailments, many of which will get better given time.
Sadly our little springer didn't have enough time to recover before general old age got her.
However, knowing that the dreaded human spector of a stroke was not the problem, made living with her strange behavior a lot easier and it didn't seem to bother her! She always got there in the end even if she took in a couple of flower beds on the way!