About 10% of dogs have allergies, said Sandra Diaz, an assistant professor of dermatology at the  Virginia-Maryland Regional College of Veterinary Medicine , in a recent  health article  by  CNN .

"Allergies we cannot cure. We just manage them and keep them under control so the animal can have a good quality of life," she said in the article.

While some allergies are caused by allergens in the air, others can be caused by allergens in petfood. Diaz said it takes many weeks to determine whether an animal has a food allergy.

She suggested starting the pet on new food, and watch for allergic reactions to it for eight to 10 weeks. If there are no reactions, feed the pet with the original food. If the symptoms return, Diaz said in the article, the diagnosis is a food allergy.