We have a 7 year old lab who is still very active. He's a domestic dog. He has been fed for many years on Arden Grange, Lamb & Rice (dry food). However over the past 18 months when we have walked him his first poo has been firm, but subsequent ones lose shape and the third/fourth poo is runny. Recently we swapped him onto John Burns, salmon & rice, which initially made a difference. However the same pattern has returned again. Has anyone else experienced this and uses a food that solves the issue?