Dog had a stroke, seizure, chronic wasting or Vertigo?

My 12 year old German Sheperd one day, was yelping, like she was hurt. She started running towards me but, was running sideways. Her eyes couldn't focus on anything and were moving from right to left, like if you had to spin around fast for some odd reason and then run. It seemed like her Eguilibrium was off. I took her to the vet and they said she was fine. They did blood work and nothing showed up. What could this be caused from?

sounds like something my dog had once. it was just an inner ear infection. she acted like she was drunk! they didnt know what it was at first and put us thru a scare, might have been a stroke, might have been a tumor and put her on steriods. but those tests came up negative and they just let her be. they told us some times dogs get it so badly, they'll roll across the floor until they hit a wall becasuse they dont know which way is up. smokey had a cocked head for a while while she was trying to make things looks straight for her, but that went away eventually. if it doesnt stop soon, like within a week, bring her back. but it really just sounds like its an inner ear problem.

My dog had that too when she was 13. It is common in older dogs and is like a miniature stroke that affects the equilibrium. She was fine in a day or so and lived another year.