pls help me .. indian ring neck wont stop picking off its scab

by christine
(mississauga)

hi i have and indian ring neck i just bought him 3 weeks ago and copule days ago i saw him picking below his bum and few feathers were gone and it was bleeding i took him to the vet the vet sticth him up and said it will heal he put a cone around his neck to avoid him from picking that area.

some how my indian ring neck is still able to pick that area and he is picking of the scab n its bleeding.. what can i do to stop him from picking off the scab so he can heal better?