I think one test is whether or not they crack between your thumbnails.....but that could be an old wives' tale (but I am an old wife!). Otherwise I should think you'd have to look at them under a microscope.
There are 2 types of dog-louse, one bites and the other sucks. They are host-specific, so they won't transmit to you or other species. The eggs do attach to hairs, so that's what it sounds like. Apparently a good insecticidal shampoo will control them.