Our now 3yo boxer was doing pretty well on Purina One fromula dog chow until he was diagnosed last year with ostioarthitis. The vet put him on Purina's JM dog chow (a perscription formaula) which seemed to work great for him. We saw loads of improvement in his overall demenor and mobility! However, that food cost $80+ a bag. Coupled with other suplements and medications he's taking, we couldn't afford to continue that diet. So we opted for Purina's Dog Chow formula for its affordability and the fact that, like the perscrition diet, it is also labeled 'complete and balanced'. He has been on the...