Your pet cannot develop an intolerance or allergy to food it has been eating for a long time.

Food allergy can occur at first contact with a food. In pets, however, food allergy typically emerges during prolonged exposure to the allergenic diet. Symptoms of suspected food allergy may not become obvious until they progress to the extreme. Signs of dietary intolerance are easily confused with many other types of allergies and skin conditions.

Food allergy in pets can also resemble gastrointestinal upset and appear as intermittent vomiting, pasty stools or severe diarrhea. Because many diseases can share the same or overlapping set of symptoms, your veterinarian will require your patience and cooperation until a diagnosis of food allergy is confirmed. A long list of medical possibilities must be considered before concluding with certainty that your pet is indeed allergic to a food.

Pets can be allergic or intolerant to fish, chicken or beef but they can also have a problem reaction to wheat, for example. One of the things you may be advised to do is introduce a new food to replace your pet’s current diet. Commercial diets that contain lamb as the sole source of meat protein are frequently substituted in pets suspected of dietary intolerance. This is because most pets have never eaten a lamb-based diet until it is recommended and therefore are unlikely to have developed any adverse response to it. If symptoms of allergy stop with a diet change, a diagnosis of food allergy is likely. It is important to note that some pets can develop hypersensitivity to lamb. No food can truly be called “hypoallergenic” because allergy is an individual phenomenon.