I have two old labradors Maisie, 11 and Jake, 12. Maisie ate poo as a youngster but evenually grew out of it. Unfortunately it has been an ongoing issue for Jake and when he feels like a 'snack' will often eat his own, and sometimes Maisie's poo! To be honest, it is something we have just learnt to live with, we have tried dietary additives in the past, but none of them ever really worked. Interestingly our little Staffie pup Alfie shows no signs of any interest in poo, so it may be a breed specific thing. Labradors are renowned for eating anything!!!