I have two labs which I shoot over and do a lot of picking up with.The younger one is 4 and has won a field trial albeit not with me. Lovely dog really intelligent with a super temperament After searching for a roe doe for 30 minutes last night ( which I eventually found 30 m from the point of shot- no visible blood trail despite heart lung shot) I am wondering if I could train him to track deer and if I did would he be ruined as a picking /shooting dog . He already ground scents and follows wounded birds as well as air scenting.However he ignores deer if he flushes them when picking up. Does any one use their labs in dual roles? If i decide to proceed what book or training manual would you recommend.