|I'm looking for an evergreen shrub, to 4'<> with thorns or spines that is also attractive
|Holly is evergreen and the leaves are spiney; barberry and rosa rugosa are deciduous, but they have thorns which would keep people or animals away. I like barberry for all year interest. While it does lose its leaves in the fall, it produces red berries which give it some winter interest.
Hope one of these suggestions is just right for your landscape.