
Well I can give you good and bad news. The bad is, when my sister's dog had it at age 12, which was not that old for him since he lived to almost 17 :), her Vet said the symptoms would last 4 to 6 WEEKS. And they did, 4 weeks. He weighed about 45 lbs and she had to carry him outside all that time. Put her back out picking him up. As he recovered he was able to walk a bit on the grass outside but could not get outside by himself and could not walk in the house.
The good news is, he made almost a complete recovery. He retained a wee bit of heat tilt which slowly lessened but never completely disappeared.
Edited to add: Sis's Vet said recovery is typically just as sudden as onset and that was also true in Laddie's case. One day he could not walk outside, 2 days later he could.