I have two cavaliers with food allergies. I didn't realize India's problems were caused by allergies until she was seen by a dermatologist at OSU. The main indicator for India's allergies was yeast that would always return after being treated. Her face/mouth always had a slight stinky smell (no matter how often cleaned), she'd been treated several times for yeast in her ears, and she had yeast stains on her feet. We changed her food several times and after we found one she could eat and not have a smelly face, our vet prescribed medicine that would completely clear up the existing yeast on her. The foods she can eat are: Nature's Variety Prairie Venison and Millet kibble, Nature's Variety Raw Frozen Lamb (not chicken, and I won't give her rabbit because one ingredient is sourced in China), and canned tripe (for special occasions). We have started to mix in a little Taste of the Wild Pacific Stream kibble with good results - her face continues to smell good. If I feed her something she is allergic to we can smell yeast around her mouth within 2-3 days. She seems to be allergic to chicken, most grains, and sweet potato. Her dermatologist pointed out that there is a small amount of chicken liver in the Venison and Millet kibble, but it doesn't bother her; however if I give her chicken in any form she immediately gets yeasty. Wheat germ is a non-allergenic part of grain, so I add a small amount of raw wheat germ to her food. We've found that India is allergic to most dog biscuits so we buy special ones from a nearby dog bakery, or prescription biscuits from OSU (made by a vet), or we give her Wellness venison jerky treats.
Geordie is sensitive to chicken and something else I haven't determined yet. I thought it was grains, especially rice, but it turns out it must be something else. Geordie is not a picky eater - he loves all food, but there are many foods that don't agree with him. I've been feeding him Taste of the Wild Pacific Stream, California Natural Lamb and Rice, Nature's Variety Prairie Venison & Millet. Right now I'm thrilled with Taste of the Wild, his newest food that totally agrees with him.
Luckily for us, Chocolate has no food sensitivities or allergies - she has eaten many different kibbles, all the foods I've bought for India and/or Geordie to try. She loves all foods!