I doubt I'm the only one that raised their eyebrows when they read the first sentence of your post! Then, to read that you train horses!!! Geez, that alone is rough on a persons back let alone already having back problems, but hey, I can't say I wouldn't have done the same thing. Especially not knowing what your back "issues" were in the '70's. Anyway, it always surprises me to hear of almost the majority of people being told to go to PT after ANY spine surgery. If everyone else's surgeries were like mine (and I believe they were), we all got a sheet to take home of exercises to do after a certain period of time anyway. So to add the additional stress of PT to that (and it was a LOT of exercises as I recall) made even the surgeon for my 3rd spine surgery balk and literally ask me how PT was going to heal anyone's herniated disc(s)!! This coming from a neurosurgeon...of course I had no answer to that because it all seems backwards to me and a lot of others who went through the same thing.
I agree with "DrVinod". It sounds like the only thing you can do is go back to the doctor and see what he says BUT THIS TIME, get a second opinion (or even a third).
As you and others now know, once the damage is done....it is DONE.
Hello!
Avoid any further physical activity and you would need further surgical correction. With the amount of stress and damage your spine has taken you should also quit training horses.
Follow up with your orthopedician for the best advice and go for present day scans.
Take care!