Back then, vets did not check for this as often as they do now and owners were told to put them down because the dog was "suffering"...It's very sad, and even to this day some vets are still recommending that pups who have it be put to sleep instead of doing the research that it takes to find out what the dog has and do what it takes to fix it.
I'm so sorry that your furbaby had to cross over the bridge
I know how hard it is to make that decision...In 2004 right before my wedding, my furbaby that I had at the time had to be put down because he had congenital disease that was paralyzing his body and causing him extreme pain. I was a basket case...they told me that in his particular case, surgery wasn't an option