My boxer has allergies; itchy skin, runny nose and sometimes diarrhea and vomiting. He had lost a lot of hair from Demodex when I adopted him. After a year when the hair had not grown back, I took him to an allergist. She told me there is no test for food allergies. She put him on a vet food, rabbit and potatoe, put him on Ketoconazole for 3 weeks because he tested positive from a skin scrap for yeast. She said that was caused from all the licking. She took him off heartworm meds and put him on Ivermectin for a month. He did great on that regimen. When we went back, she gave me 3 names of dog foods to try; Natural Balance Duck and Potato, Natures Recipe Vegetarian, and Wellness. She didn't specify which Wellness so I started him on Natural Balance. He did okay but not as good as he did on the vet diet. After a while he started getting sick on the Natural Balance and I found out they changed the ingredients and that could be causing the problem, so I switched him to Natures Recipe. I'm still trying to find something as good as the rabbit and potato. So far no luck. She told me the #1 food allergy is corn, followed by chicken, pork, wheat. The only way to find out is to feed him exclusively 1 ingredient at a time for 10 days and see how he reacts. I started with chicken, he had what sounded like an asthma attack after 2 days of strickly chicken and then broke out in hives. Same thing when I fed him popcorn, that same night he broke out in hives. I quit with the food challenge. Now I'm researching other foods to try him on and am going to switch to Ivermectin instead of Heartgard or Sentinel. Sentinel is what I had him on and she said it has pork in it. With Heartgard, he got sick. Looking at trying Acana Pacifica next or a new food I found here in our area called Nature's Select. It is made here in Austin. Not sure about it yet. Wish me luck.