What size/number clipper blades are generally used for horses and what size for dogs?

Oh the horses, I usually use a #10 blade on the muzzle, throatlatch, ears, and bridle path. For most dogs, I use a #7 all over. Some customers ask for it a little longer, so if the dog isn't matted I'll use a #5 or #4 (but only on dogs that are totally mat free, and they don't work very well on double coated dogs) I find that the #7 leaves a nice smooth finish, and goes through most mats. For really tough mats, I use a #10 (but only on the mat, if used all over, the poor pooch would end up naked!)