It is most likely diet related unless you recently used a flea med or washed her in something new. Most dogs are allergic to grain found in most kibble, your dogs allergic reaction is a more severe one it sounds like. Dogs are carnivors. And I'm positive they never cooked their food. I feed my boy all raw meat. This is by far the best diet I have come across. All kibble causes tarter which leads to a plethora of health issues. Feeding raw isn't easy but it is very worth it in the long run. It provides healthier coat and skin, better muscle and joint development, less allergic reactions and health issues associated with them(skin irritation, dry skin, ear infections, respiratory infections, etc.), gets rid of tarter and bad breath, reduces shedding and even reduces the amount of waste the dog produces because the dog can absorbed the nutrients in raw meat. Dogs are not designed to break down grains and vegetables. Almost all dogs have allergies to grains, severe or mild. Im not one to let my dog suffer the consequences just because kibble is so convenient. And don't get me wrong, I fed kibble before I researched dog nutrition and talked with numerous dog nutritionists and vets(don't be fooled, most vets do not receive proper training on dog nutrition. They receive a list of required nutrients and are trained only to insure that those nutrients are included in the diet. They do not pay attention to how important HOW they get those nutrients is. It's like a child being forced to eat mcdonalds cheese burgers their whole life. The burger has most essential components of a balanced diet: grain, protein, dairy and vegetables, but its not healthy. Kibble has all the nutrients in theory, but it is not healthy.). If I had to feed kibble it would be grain free Fromm four star. And I would make sure I incorporated a lot of raw meaty bones to help clean the teeth. If you are interested in feeding raw, do your homework. There are alot of components but its really not hard once you do it a few weeks successfully. This is my meal plan for my dog. Its a combination of lots of resources. It works well for me. I use mainly venison(we hunt), chicken, beef, pork, duck, and turkey. Any meat will do. Lamb is a favorite treat for mine. Variety is always good. I don't get these exact percentages every meal but every month comes out to about these percentages.
20% RMB(raw meaty bones)
13% Green Tripe(unrinsed, uncooked, nonbleached ruminant stomach)
5% Other Organ(kidney, lung, pancreas)
50% Muscle Meat
7% replacement meals and supplements from other sources(whole animals: squirrel, rabbit, fish; eggs with shell, raw unpasturized goats milk, salmon oil, vitamin E, raw unfiltered apple cider vinegar)