Riggs situation sure is strange. I know EVO is high protien, maybe he is not adjusting well to it from what he was on before. I'll say this, I am a firm beleiver in Salmon oil, from coat and skin, to providing heart health and other benefits, and kelp for coat and skin. Between the EVO and the raw eggs, he might need a little extra supplementation.
If you do switch to RAW, I always recommend some type of supplements to make sure they are getting everything they should. Once again, mine get Salmon oil everyday, and I alternate the kelp and Nupro/Missing Link. I always rotate supplements so the dogs are getting what they need, and I was told by a holistic feeder that rotation is very good for their bodies. For RAW, mine get chicken, duck, turkey, beef, salmon, whole mackerel, buffalo, chix ribs, necks, duck carcasses and necks.
They eat better than we do
I treated my girls condition with a month of cephalexyn ( 1,000 mg a day) and a rinse/treatment from Equine Elite called Rain Rot Relif. I actually always keep this on hand, it does wonders for coat and skin conditions, and they have a wound relief also.