Dog allergy

Sophie Matzik is a freelance writer for the medical team.

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A dog allergy is an over-sensitivity of the immune system to certain substances that are released by dogs in saliva, urine and glandular secretions. A dog allergy manifests itself through symptoms such as reddened eyes, the urge to sneeze and a runny nose. Depending on the severity of the symptoms, dog allergies are treated differently. Read everything you need to know about dog allergies here.

ICD codes for this disease: ICD codes are internationally recognized codes for medical diagnoses. They can be found, for example, in doctor's letters or on certificates of incapacity for work. J30

Dog allergy: description

The dog allergy (dog hair allergy) is an oversensitivity to certain, actually harmless proteins that are given off by dogs. These proteins are found in saliva, urine, and skin and sebum glands. They are found on dander and hair as well as in the dog's urine. If the dog's allergens get into the respiratory tract and on the mucous membranes of humans, they can cause an allergic reaction. Contrary to popular belief, it is not the dog's hair itself that causes an allergy, but rather particles that stick to it.

The dog allergy is the second most common allergy to pet hair after the cat allergy. Dogs generally produce all allergens. There is no breed of dog to which this does not apply, although rumors about it have been circulating over and over again. In contrast to cat allergies, in which those affected are mostly allergic to all types of cats, a dog allergy can only exist against individual breeds. For example, more people are allergic to boxers than to German shepherds. There is evidence that short-haired dogs are more likely to cause problems than long-haired ones.

A few people with dog allergies show signs of allergy even when they come into contact with cats. Dogs and cats basically produce different proteins, but some of them can be similar in their basic structure. It is much more common for people with cat allergies to develop allergic symptoms when they come into contact with dogs. This phenomenon is known as cross allergy.

Dog allergy: symptoms

In the case of a dog allergy, the symptoms appear immediately after contact with the allergens. Dog hair allergy is an allergy of the immediate type. This means that immediately after contact with the allergen in dog hair allergy symptoms. No direct contact with dogs is necessary to trigger allergic symptoms. The canine allergens can also be transmitted through the air, objects, or other people.

The symptoms of a dog allergy depend on where the contact with the allergens occurs. If they get into the eyes of an allergic person, they develop red, burning or itchy eyes up to and including conjunctivitis. If they are inhaled and get into the nose, for example, the symptoms are reminiscent of hay fever. There is increased secretion production, the mucous membranes swell. Often there is a permanent urge to sneeze. The mucous membranes in the throat also swell. Coughing, difficulty swallowing and sore throat occur. Some skin may become red or swollen when they come into contact with the allergen.

Compared to a cat allergy, the symptoms of dog allergies are often less pronounced. If an allergy is left untreated for a long time, symptoms can get worse over time. In rare cases (especially if a dog allergy has not been treated for a long time or in the case of very high allergen exposure), asthma attacks with breathing difficulties and shortness of breath or even anaphylactic shock can threaten.

Dog allergy: causes and risk factors

Dog allergies are caused by certain proteins that are released by dogs with their saliva, urine and skin glands. These proteins (allergens) adhere to the dog's skin flakes and hair. From there they either get into the room air, onto objects or through direct contact immediately on people.

The canine allergens are actually harmless substances. The real cause of dog allergy is an overreaction of the immune system. When the immune system comes into contact with the substances for the first time, there are no symptoms of an allergy. However, the immune system recognizes the substances as foreign and classifies them as harmful. As a result, it makes antibodies against them. When the allergens come into contact again, the antibodies are activated. These now stimulate cells in the body that release histamine, among other things. Histamine triggers swelling of the mucous membranes in the body, increased mucus production and widening of the blood vessels.

In order to develop symptoms of a dog allergy, sufferers do not even have to have contact with dogs themselves. The allergens are distributed throughout the air and by pet owners who wear dog hair and flakes of skin on their clothing. High concentrations of allergens can therefore also be found in public places such as schools or on public transport. A dog allergy can therefore also occur in people who have never had personal contact with a dog.

Dog allergy: examinations and diagnosis

If you suspect a dog allergy, your family doctor or an allergist is the right contact. In a first conversation, he records the medical history (anamnesis). You have the opportunity to describe your complaints in detail. To narrow down the types of symptoms and possible causes, the doctor may ask questions such as:

Do the complaints mainly occur indoors or also outdoors?
Do you have permanent complaints or do you have intermittent symptoms?
Do you have pets?
Have there been people in your family with similar complaints?

Due to the multitude of possible causes of an allergy and also because the symptoms can point to other diseases, the diagnosis of an allergy can be very difficult. A physical examination will take place after the first interview. Among other things, the skin, eyes and airways are examined. The lungs are listened to and general health checked. The doctor may ask you to come a second time and keep an allergy diary in the meantime. Enter the following in an allergy diary:

When and where the complaints occurred.
What you just did.
What you ate and drank that day.
What medication you have taken.
What possible causes would be.

If the doctor has made a suspected diagnosis, an allergy test is carried out. The so-called prick test is usually used as an allergy test today. Possible allergens are dripped onto the skin (usually on the forearm) and the skin underneath is slightly scratched. If there is a dog allergy, the skin under the relevant allergen will redden within 15 to 20 minutes, swell up and possibly form pustules. If there is no allergy, the prick test shows little or no skin changes.

In addition, a special blood test can be carried out (so-called RAST test). The blood is tested for antibodies that indicate an allergy. A normal blood count can also rule out inflammations and infections of the body, which can be associated with symptoms similar to those of dog allergies.

If the results are uncertain, a provocation test is carried out. To do this, the suspected allergen is applied directly to the nasal mucous membranes. The provocation test is rarely used today because it can cause very severe allergic reactions. After the test, a follow-up observation of at least half an hour is necessary.

Dog allergy: treatment

The symptoms of dog allergies are generally less pronounced than those of other allergies. In many cases it is therefore sufficient to avoid special risk factors for treatment. If you have a dog allergy, you should first avoid any contact with dogs. In the case of a severe dog allergy, a dog who lives in the household must be handed over.

Dog owners who have developed the dog allergy in the course of their lives often find it difficult to part with their pet. If the dog allergy is only mild, this is not absolutely necessary. Initially, only direct contact with dogs should be reduced. You shouldn't let your dog lick your face, hold your dog on your lap, and wash your hands thoroughly after each touch.

Medication
Various drugs such as antihistamines or cortisone preparations are also used. These are used to treat the symptoms, but not to eliminate the cause. They can alleviate acute symptoms. On the other hand, they can also be taken preventively, for example if a visit to the house of a dog owner is planned.

Desensitization

If the dog allergy is associated with a significant reduction in quality of life or if there are very strong symptoms, then hyposensitization is also an option. The allergen to which the body reacts is administered directly in increasing doses over a period of several years. It can either be injected under the skin (subcutaneous) or dripped under the tongue (sublingual). The easiest way to explain the effect is using the principle of habituation. By administering higher and higher doses, the body is used to higher doses of the allergen and no longer reacts to lower doses with symptoms. If symptoms reappear in the course of life after being desensitized, this treatment can be repeated at any time.

Dog allergy: disease course and prognosis

The course of the disease and prognosis of a dog hair allergy depend primarily on the behavior of those affected. If the cause of the allergy (dogs) is consistently avoided and you do not have your own dogs, the symptoms can usually be reduced well. If exposure persists, symptoms may worsen over a lifetime. In extreme cases, a dog allergy can develop into bronchial asthma with permanent symptoms.

After a desensitization there is usually a favorable prognosis. If allergy triggers are avoided in the future, those affected by dog allergies have a good chance of leading a symptom-free life. In many cases, however, the symptoms of a dog allergy are so weak that they hardly affect those affected.

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