Food sensitivities in a dog may manifest as
itchy skin, scratching at ears, shaking of the head, licking and biting at the hind quarters or feet, rubbing faces on carpeting, ear inflammations, coughing, and rarely vomiting, diarrhea, flatulence, sneezing, asthma like symptoms, behavioral changes, seizures, gagging, and vomiting.
Contact Allergy
Contact allergy is the least common of all the types of dog allergies.