Claybird,
I probably do about 50 of these surgeries on dogs each year. As many people know, ruptured ACLs are a very common injury in human athletes, especially football players. Even with the best surgeons and unlimited technology available to MDs it can still be a career-ending injury for them. On the other hand, they are usually able to at least regain normal usage, even if they are no longer competitive. A hunting dog falls somewhere in between "normal usage" and playing football. Your results aren't unusual, even when done by the best in the field. We can never make it as strong as it was originally. You asked what you can do? GET the weight under control! Whatever it takes. Stress on the joint is multiplied exponentially by obesity. Other than that, there are a few options, including glucosamine/chondroitin products like Cosequin, Omega 6 fatty acid-containing diets like Purina's prescription line (CNM) JM diet (maybe it's JD? can't recall right now), Adequan injections (a precursor to the normal joint fluid which provides lubrication), and finally anti-inflammatory meds (NSAIDS like Rimadyl, Deramaxx, etc.) to treat the pain and reduce inflammation. There are some clinics who offer physical therapy in heated underwater treadmills. We don't, but I have heard of good results. I would make sure if I went this route that the vet is certified in this type of therapy. It's a lot more complicated than just putting them in for a half hour a day. I believe that you can find a workable solution, but it may take some time (and money unfortunately). She may not ever be able to hunt as long and hard as she once did, but hopefully she can hunt enough to be useful. Come to think of it, I can't hunt as long and hard as I once did, either. I would stop her for the day when the lameness begins to show. Lameness means pain, which means inflammation. Chronic inflammation means chronic arthritis, which is irreversible.
As to the original subject of this thread (not Claybird's dog), my advise would be to feed a good quality food from one of the major manufacturers (Hill's, Purina, Iams). There are lots of niche manufacturers out there touting their high-quality ingredients and all-natural whatever. But the fact is, they are small-time compared to the big guys, and don't have the money to do the extensive research done by the big manufacturers. I have seen the research facilities and exhaustive studies done by the majors, and it cannot be approached by the niche makers. Neither can they match the quality control. Just recently, there was a large recall of the Diamond brand food due to contamination with aflatoxin - a potentially fatal toxin produced by fungal contamination of the grains used. There were quite a few sick dogs and some deaths associated with this recall. So-called "high-protein" foods are appropriate for dogs that are hunting/training hard every day, but probably not for the weekend warrior or in the off-season. If the dog isn't working extra hard, it can't use the extra protein, therefore it becomes a waste product in the blood which can be hard on the kidneys especially as the dog gets older.
Recently Purina did a study of about 15 years where they took littermates from many, many different litters and put one littermate in each of two groups. One group was fed only enough to keep the body condition just below what is considered normal (in other words, a little thinner than what we consider normal). The other group was fed more, so that they were just slightly overweight compared to the accepted norm. The underweight, a-little-too-thin dogs lived about 2 years longer, on average.
