If the skin is itchy and the stomach hurts, a feed allergy may be to blame. It is important that you, as the owner, know the difference between an intolerance and an actual allergy. Read here what can trigger an allergy and how you can find out whether your dog suffers from one.

The typical symptoms

Externally, both the dog’s food allergy and the intolerance to certain foods make themselves felt through the same symptoms. This includes:

The difference, however, is that the immune system is involved in a feed allergy – not in the case of an intolerance.

Severe itching can indicate an allergy. © stock.adobe.com/malivoja

Feed allergy vs. intolerance

Even the smallest amounts of the allergenic (allergy-causing) food component usually cause violent reactions in the case of a feed allergy. The form in which the allergen is absorbed also does not matter: cooked, raw, served as a flavor carrier or as part of a medication, the dog’s body reacts to it.

In addition: In the case of a food allergy, the dog reacts permanently to this food component. If the dog always eats the same food, but only shows irregular symptoms, it is probably not a food allergy.

In the case of food intolerance, on the other hand, the dog’s body reacts particularly sensitively to certain ingredients such as lactose or gluten. The dog can also be deficient in essential digestive enzymes that prevent these ingredients from digesting properly. The symptoms are usually more severe the more the dog consumes the ingredient.

Whether raw or cooked – dogs can always have an allergic reaction. © stock.adobe.com/zontica

Trigger of a feed allergy

Whether in dry or wet food or in treats: The following ingredients are most often found in conventional feed and are therefore most consumed. That’s why they top the list of the most common triggers for food allergies in dogs:

“Since many dogs have contact with one of these feeds, the proportion of allergy sufferers among them is naturally higher than with other ingredients. In the USA, for example, the number of soy allergy sufferers is particularly high because more soy is used in feed than there with us, “explains nutrition expert Dr. Julia Fritz.

An allergic reaction to feed is always due to the animal or vegetable proteins. If the dog reacts to fat, sugar or carbohydrates, it is more of an intolerance. Likewise, the often demonized additives and preservatives are unlikely to be triggers.

Dogs can be allergic to various ingredients. © stock.adobe.com/annaav

Risk of a feed allergy

In a healthy dog, the risk of a food allergy is very low. Because the intestinal barrier ensures that only the food components that have been completely digested into their individual components reach the organism. However, if the intestinal mucosa is damaged and inflamed, this natural barrier does not work. Molecules that are too large then penetrate the organism. The immune system evaluates them as hostile and fights them.

A study by the University of Munich also shows that certain dog breeds have an increased risk of developing a food allergy.

Dog breeds with an increased risk of a feed allergy:

• Golden retriever
• West Highland White Terrier
• German shepherd dog
• White Swiss Shepherd Dog
• boxer

However, the age and sex of a dog do not play a role as a risk factor.

Shepherds are more prone to food allergies. © stock.adobe.com/Кристина Корнеева

Suspected feed allergy – what to do?

If your dog shows the symptoms described above, it is first necessary to clarify what the causes are. There is not always a feed allergy behind it. You can do this:

In the elimination diet (exclusion diet), only a single protein component and a single source of carbohydrates are fed that the dog has never eaten. The dog is therefore probably not yet allergic to these. If the symptoms improve on the elimination diet, you can assume that the dog has indeed developed a food allergy.

As an alternative to the elimination diet, blood tests can also help diagnose a dog’s food allergy. The antibodies that have been formed on various feedstuffs are examined. The hit rate for finding out the allergenic components is very high. On the other hand, the statement about which components are suitable for the dog is rather unreliable.