Following CCL surgery (either type) the odds are over 20% that the other knee will blow within two years. One of the best ways to help prevent this is to have your dog on a quality Glucosamine supplement
You can start here then. Not about the odds of the other knee blowing but the justification for stating that glcosamine supplements are one of the best ways to prevent cruciate tears. Could you provide literature on a quality product as well. From someone other than the company making it of course, or one of their competitors.