The problem with recommending deer-resistant plants is that a deer will eat anything if it is hungry enough! (Oh, deer!) Though it doesn't have thorny leaves, Linebacker Distylium would be a perfect solution for your hedge. Once established, it can tolerate a wide range of conditions including drought. It grows fast and matures 8-10' x 6-8'. Another plant to consider for your hedge is Sky High Juniper. Again, no thorns, but it wouldn't be much fun for deer to walk through a hedge of junipers. It tolerates dry soil conditions and matures 12-15'. Both distylium and juniper are deer resistant. Your local garden center should be able to help you with other recommendations.