Pero doesn't look too bad to be honest, not a food I'm too familar with though. Orijen is the only dog/cat food that I would ever recommend to anyone and that would obviously be second to a raw diet. That has 500mg/kg of glucosamine guarenteed but it's £40 for 13.5kg. Are you wanting to go all raw? I think it would benefit your lab with the dodgy elbow, it would probably eliminate the need for added glucosamine as raw bones contain an abundance of glucosamine, chondrotin, collage and calcium among other nutrients which are all good for healthy bones and joints.