Crio, I'll answer your question.
If your dog is getting sick off of one protein source, try another. Many dogs have developed an intolerance to chicken, for whatever reason. Also, detox can be pretty nasty. There's not a single form of detox, be allergy-related, GI cleanse, alcohol or drug, that is "pretty". I'm trying to find where I hid this link again, but it was from a Great Dane breeder (sheer coincidence, I promise you). She feeds a raw diet (not sure if it's PMR or BARF or whatever) and she said that when she first switched her dogs, it was horrific. Their skin got all nasty, the coats went to hell and they had off and on diarrhea. But once the detox period was over, about a month for it all to totally subside IIRC, then she saw the gleaming coats and amazing muscle tone that most people get on a raw diet. So sometimes it does seem like a horrible thing to switch the dogs over, but once they get over that rough patch, it's all good. The skin is the largest organ in the body, so when a full-body detox is going on, the body will use it's largest organ to help purge the toxins, so in this case, it's the skin.
Heck, I wondered if I was doing the right thing this spring when switching Sawyer grain-free/EVO there for a bit...had a week of runny, watery stools and a ridiculous amount of shedding. I added some *gasp* pumpkin and yogurt to his food, washed his pants out three times a day and brushed him till I thought he should be bald. Then everything evened out and it's all been good from there. I did switch away from the reg. EVO though, he was leaving urine burns in the lawn and those did go away when I put him on Nature's Variety INSTINCT.