There are many signs that your dog could have a food allergy. The list is almost endless, but the main culprits are itchy skin, a dull and/or frizzy coat, inflamed ears, excessive licking of certain areas (paws for example), lethargy, diarrhea (even projectile stools), blood, mucous or both in the stool, gas and possibly even vomiting. These, coupled with horror stories of owners coming home from work to find their living rooms sprayed with sick-dog diarrhea can all be symptoms of dog food allergies. Some symptoms can be a lot more dangerous, like seizures or negative behavior changes. When dealing with your dog's food allergies you need to understand, change and monitor the dog's diet and reactions.