In MOST dogs my recommendation is to NOT pluck their ear hair (and to not have the groomer do it). Plucking hair from a happy normal ear canal can cause inflammation and introduce an environment that welcomes bacteria/yeast overgrowth. However in some dogs they have so much hair growth within their canal that its presence acts like a foreign body in the canal and leads to infections and irritation. It can also prevent the ear from drying well after swimming/bathing which contributes to infection