He needs to be seen by a vet. Some of the symptoms you have described could be neurologic. They could be a result of trauma, stroke (yes, horses can have strokes) or certain diseases.
What is his vaccine history? Is he vaccinated for rabies? What area of the country do you live in and what are his living conditions? Closed herd on private property or boarding/training/show stable with lots of horses coming and going?
If he is 34, you do need to start monitoring him and possibly feeding him with choke in mind, though I don't know that the current problems are choke related at all. They possibly could be - not all chokes present with drastic symptoms. There is a pretty good chance that he doesn't have many teeth left, and what teeth are present are probably nubs. Floating isn't as big of an issue in extreme elderly toothless horses, because they simply do not have enough opposing teeth present to create hooks and waves. Anyway, he would probably appreciate water soaked feed and soaked chopped forage/cubes. He may soon (if he doesn't already) have trouble maintaining his weight.
My current horses are aged 37, 29 and 8. My old guys have been on "liquid diets" for years.
