I don't have experience with CCL injuries myself, but I know that they can be tricky and hard to diagnose sometimes. A brace might help minor damage heal, but I think ultimately, surgery is often needed.
The only other thing I can think of is to try chiropractic: www.avcadoctors.com
I had a dog that the vet thought had a knee injury, and it was actually an SI joint. In fact, I had to try 3 chiros before I found the one that could get at the problem, it was jammed in a really funny way. I ultimately found a chiro that also worked on humans and horses that was also very good at working on extremities.
I used to have bowen therapy done on myself (love it), but I still needed chiro treatment, and have continued with.