Skip navigation [Access key S] Homepage [Access key 1] Go to the sitemap page [Access key 2]. Go to the legal disclaimer page [Access key 3]. Go to the contact page [Access key 4]. Go to the accessibility statement page [Access key 0].

Hypo-allergenic dog food range

Designed to be kind to your dog's stomach

The role of the immune system

The immune system is a complex system that can be compared to a defending army: always ready to protect the body against attackers such as viruses, bacteria, fungi and other foreign invaders that may cause harm.

The troops

The immune system can be divided into two distinct parts: the first line of defence is the so-called innate immune system. Examples include the skin, which essentially acts as a protective shell against invaders, and the stomach acid by killing off most bacteria from food.

In a food allergy,
the immune system
simply overreacts
to a stimulus
If an invader manages to get past this first line of defence, the so-called adaptive immune system comes into action. Its response is tailored to a specific type of invader, and it displays memory, responding better after the first exposure to an invader.


Different types of white blood cells perform the main tasks of the immune system. While some of these cells simply kill the invader, others produce so-called antibodies ("Immunoglobulins") specific to that particular invader profile. These antibodies bind to the invader, thereby deactivating it and making it an easier target for killer cells.

Memory cells

Certain cells of the immune system become memory cells after they've been exposed to an invader: They will remember this specific invader and will be able to launch a more powerful and quicker immune response when they have any future contact with it. This is the precise mechanism that makes vaccination effective. Your dog's immune system develops memory cells for the particular virus that is administered with the vaccination. If the dog then comes into contact with this virus in a real life situation, the immune system is already prepared and can react swiftly.

In a food allergy, memory cells have been formed for harmless proteins found in food.

What happens in an allergy

For reasons that are not fully understood, the immune system doesn't always function properly. In a dog with a food allergy, the immune system mistakes food, most often protein, for an invader and mounts an attack. It is therefore the immune response that causes the symptoms, and not the substance itself ("allergen").

In a food allergy, the immune system simply overreacts to a stimulus. Immune cells are wrongly alerted to harmless proteins and perform their actions, and antibodies are produced to target those proteins that are not foreign attackers.

In addition, various other cells can also be activated during an immune response. These cells release chemicals such as histamine which causes inflammation - one of the main symptoms of an allergy.

With ongoing exposure to the allergen, the inflammation can become chronic and manifest itself in other parts of the body than the digestive tract, such as in symptoms affecting the skin or recurrent ear infections.


The hypersensitive immune system of a dog with an allergy to one or more food proteins can recover over time if these protein sources are excluded from the diet. The period of the exclusion diet can also give the dog's digestive system the chance to regain health.

The mucous membrane of the gut is part of the innate immune system and populated by billions of "good" bacteria. When the intestinal flora becomes imbalanced, as can happen in food allergies, the dog may become more susceptible to illness. For instance the dog may suffer from diarrhoea which then affects the absorption of key nutrients. So-called prebiotics which are certain types of fibre stimulate the proliferation of the "good" bacteria and help the dog regain digestive health.

Read more about exclusion diet.

Back to the top of the page Back to top

About our ingredients

Only the best ingredients are used in H-Allergen HA+ which is why you can rely on it to be easily digestible.

More about
our ingredients

Where to buy H-Allergen HA+