Same prob here baring eating poooooo let her of in woods for a run every time i shouted her she ran off it took 30mins + to get her back so back on lead yet again and back to basics its 1 step forward 3 back
Get some good wormer down him the put him on Pasta and tripe or just tripe and dry mix and maybe a raw egg on top and mix it all up and dont keep changing his food that may give him the sh*ts