@slider7420 I am not a vet, not even close. My dog, Moka, is about 13 or 14 (she came to us from a shelter about 11 years ago). Almost exactly a year ago she suddenly started to show similar symptoms as you describe, from one minute to the other. I was sire it was a stroke, but I was wrong. Back then, I had some really sad days. But she improved over a week or so. She is not the same as before, but she enjoys a (very slow) walk. With a medication called Karsivan she can also easily relax, where she was very nervous before. Large stairways no longer work for her, but she still enjoys her food as well as an occasional treat.
@slider7420 I really hope that Rufus will be good again. My feeling is that Moka still is a happy dogs; dogs are modest creatures, who are willing to take what comes.
@underlander Yeah I have heard similar things from several people. I hope he will be able to navigate stairs again because his favorite thing in the world is to go for car rides. He had been using stairs to get in and out of the car. Unfortunately he is a 90 lb dog that hates being picked up. Getting him in and out of the car to go to the vet has been a fight. Leisurely joy rides might be a thing of the past if he can't use the stairs.