It generally results in a difficulty for the animal to digest its food either because it is not digestible enough, or because its energy concentration is insufficient or because one of the ingredients that compose it is of poor quality. In dogs and cats, food intolerance is often confused with allergy because they both result in the same symptoms but food intolerance does not involve the immune system. Milk and diets too rich in cereals can therefore be the cause of food intolerance.
It is an exaggerated reaction of the dog's immune system, linked to the contact between it and an allergenic agent. The allergy is most often manifested by an intense pruritus (or itching): the animal scratches abnormally which causes lesions.
To demonstrate a true allergy, it is necessary to succeed in associating the symptoms of its manifestation with the ingestion of a specific food.A dog who suffers from a food allergy will be recommended by his veterinarian for a hypoallergenic food. He must in all cases avoid consuming household preparations whose compositions are difficult to control.