Disease and Prevention

I have spent so much time looking for a cure and prevention for dogs cataracts and I am very disappointed with local vets that think the only solution is going to a dog eye surgeon and spending a fortune having them removed. The better way is prevention, as I read it looks as if a lack of certain amino acids seems to be the culprit, then why is it not best to add those amino acids to the puppy foods and prevent this terrible disability that causes so many dogs to loose their quality of life. I will keep researching. My doxie that I had several years ago died a few months before she was 20 years old, I heard on the news that the oldest dog just died and I think I heard correct when they said it was a doxie and he was 21. Did I hear right?