I've mentioned several times that I feed my dogs a raw diet. I've also been mentioning the various things that I add into their diet. One such "additive" are raw eggs. I usually add a single raw egg to each dog's morning meal three times a week. I used to also include the egg shells, but Bess was the only one to eat them for a while and then she got tired of them and they started to make quite the mess around her crate. Heffner would just pick them up out of his bowl and drop them on the ground. Also creating a mess. So I don't even bother any more!
Raw eggs are a great source of protein as well as other vitamins and minerals. When buying non-organic eggs, it's not a bad idea to rinse the egg first. Most commercial eggs are first sprayed with a preservative to help prolong their shelf life. This is more of a concern if you choose to feed the shell. However, I've found that little shell bits seem to find their way into the bowls no matter what.
Some people may be concerned that feeding raw eggs can lead to a biotin deficiency. Avidin that is contained in the egg whites, can bind to biotin and thus make it nonabsorbable by the body. However, it would take a whole heck of a lot of avidin (more than is contained in the average egg white) to create a potential problem. Not to mention, raw eggs aren't the only thing that you would be feeding your dog.
If you're interested in more information on the subject, I've found these sites to be generally helpful in addition to reading books and magazine articles: