Dog allergy: causes and symptoms

In France, 7 million dogs live in our homes, delighting kids and adults alike. But not all of them... Unfortunately, pets are one of the most common causes of allergy, and the number of cases of people suffering from allergies to dogs is rising all the time.

Sneezing, coughing, itchy throat, watery eyes, etc. Allergies to dogs can closely resemble allergies to pollen or house dust mites, and can be a real nuisance in everyday life.

Fortunately, in this article we explain how to identify a dog allergy, what the symptoms are and the essential steps you need to know in order to cope.

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What is a dog allergy?

An allergy is an excessive and inappropriate reaction by the immune system to a normally harmless substance. Thinking the body is in danger, it sets up a defence strategy and releases antibodies and the histamines responsible for allergic reactions which include skin reactions, breathing difficulties, swollen eyes, etc.

An allergy to dogs is in fact a reaction to allergens carried by dogs. These may be molecules contained in their saliva, urine or skin. These molecules generally enter the body via the respiratory tract.

There may be multiple exposures to these allergens before the allergy develops. This is known as the "sensitisation" phase and can last for months or even years.

During this period, certain allergen molecules are stored by the body so that the immune system can prepare its defences. When an allergy occurs, the mast cells responsible for protecting the body release histamine, which reacts to the perceived threat with a localised inflammatory response which varies in severity.

Is it possible to be allergic to dog hair?

Dog hair is not allergenic per se. But when a dog licks itself, it 'allergens' its hair, i.e. it deposits allergens on its coat.

On a daily basis, dogs walk around and deposit hair all over our homes. These hairs quickly fill our various living areas, our furnishings, from carpets to curtains, our sheets and our clothes, increasing the risk of exposure.

What causes allergies to dogs?

It is not dog hair that is allergenic, but the molecules it carries. These allergenic molecules are the main causes of allergy to dogs and most often come from proteins present in:

  • The animal's saliva

  • Urine

  • Dander, small flakes of dead skin

  • Secretions from the sebaceous glands, which produce sebum at the base of the coat

  • Secretions from the anal glands, which contain pheromones.

A dog's coat can also carry environmental allergens such as pollen, dust mites and mould, exposing us to them through physical contact, for example.

How can I tell if I'm allergic to dogs?

  1. Identify the symptoms. Consult the list of common dog allergy symptoms and see if they apply to you. How do you react when you find yourself in the presence of a dog? There are certain signs that can tip you off: sneezing, watery eyes, itchy throat, etc.

  2. Do an allergy test. An allergist can carry out an allergy test to check whether you are allergic to dogs. This usually involves a general questionnaire about your symptoms and living environment, skin tests and sometimes blood tests.

  3. Try desensitisation. If an allergy is confirmed by your doctor, you can try a desensitisation programme. This involves gradually exposing the body to allergenic molecules so that it becomes accustomed to them. This is a long-term treatment, generally lasting several years.

What are the symptoms of an allergic reaction to dogs?

Breathing difficulties

An allergic reaction to dogs generally manifests itself in the respiratory tract and resembles allergic rhinitis. We then notice:

  • Sneezing

  • Nasal congestion

  • Nasal discharge

  • An itching sensation on the roof of the mouth or throat



Eye reactions

These symptoms are often accompanied by disorders of the eye, similar to conjunctivitis:

  • Watery eyes

  • Itchy eyes

  • Redness of the eye or eyelid



Skin reactions and dermatitis

Physical contact with a dog can also cause an allergic skin reaction. The allergic person may then observe the following on their skin:

  • Red, dry patches (eczema)

  • Hives

  • An itching or burning sensation

Whatever the nature of the symptoms, they generally appear within minutes of exposure to the animal.

Could there be complications?

In rare cases, the symptoms of a dog allergy can become more severe. In these cases, you need to be particularly vigilant and see whether the symptoms involve:

  • Breathing difficulties: wheezing, coughing, asthma attack

  • Angioedema: swelling of the face or airways

  • Anaphylactic shock: paleness, malaise, difficulty swallowing saliva, etc.

In this case, it is essential to call the emergency services immediately.


Children and babies

If you suspect a child or baby is having an allergic reaction, call the emergency services immediately.

Recommendations: how do you calm down an allergy to dogs?

  1. Avoid contact with this dog. That's your top priority! Any physical contact between the animal and the allergic person must be avoided. The allergic person should not remain in the area where the dog lives.

  2. Take a supplementary treatment. Depending on the case, this may involve antihistamines, corticoids, decongestants, nasal drops or eye drops, all of which can be prescribed by a doctor.

  3. Follow an in-depth treatment. In other words, desensitisation. It takes time, but it is the only alternative available today for treating the root of the problem.

How can I become desensitised to my dog allergy?

Allergy desensitisation is also known as "allergen immunotherapy". The aim is to reduce sensitivity to an allergen by gradually but regularly exposing the body to small quantities of that allergen.

The stages of desensitisation.

  1. Consult an allergist. An appointment with an allergist allows you to assess the nature of your allergic reactions and your state of health. In order to make a diagnosis, he or she will ask you a series of questions about your reactions, the triggers, your living environment, etc.

  2. Allergy tests. Secondly, if the doctor suspects an allergy, he or she will carry out blood and skin tests. These tests are used to confirm a diagnosis and determine which dog allergens you are sensitive to.

  3. Treatment strategy. The test results will enable the doctor to determine a personalised support and desensitisation strategy.

  4. Immunotherapy. Immunotherapy can vary in terms of how long it takes, depending on the allergens and the individual. It can last from several months to several years. During this period, the doctor may give you regular doses of dog allergens, in the form of injections or sublingual drops. The doses are gradually increased until the body develops a tolerance.

  5. Maintenance period. Once the allergist has found an effective maintenance dose, you will continue to receive regular doses to maintain your tolerance to dog allergens.

Expert advice

Numerous studies have shown that keeping a pet can have a number of health benefits for children. In fact, close contact with a cat or dog from childhood can strengthen the child's immune system, reducing the risk of developing asthma or allergies, for example.

My advice: adopt one of these adorable little furry creatures!

Find out more

Can you become allergic to dogs overnight?

Yes, unfortunately it is possible to become allergic to dogs from one day to the next.

Our immune system is dependent on many internal and environmental factors: our state of health, stress, hormonal changes, the climate or the place where we live, and so on. This means that our level of sensitivity is not the same throughout our lives.

What's more, the sensitisation phase to an allergen can take varying lengths of time. Some individuals may be exposed to allergens for years before developing an allergy.

The same applies to most types of allergy.

What should you do if you own a dog?

Have you owned a dog for years, you look after it, you love it and have no plans to part with it? Don't panic. Allergic reactions to dogs are rarely virulent. And there are a number of simple techniques and habits that can help you live with your pet:

  • Reduce the amount of hair that gets deposited on things. For example, you can ban your dog from going in the bedrooms or climbing onto sofas. You can also vacuum regularly to prevent hair from accumulating in your home, and buy a removable basket to make it easier to pop in the washing machine.

  • Brush your dog often. Brushing your dog regularly will prevent it from shedding all over your home. It's best to brush your dog outside or in a tiled bathroom, especially during the change of season when dogs tend to shed more.

  • Air your home every day. Just 10 minutes a day is enough to refresh the air in your home and remove any airborne allergen molecules.

Is it true that there are hypoallergenic dog breeds?

Yes and no. Technically, all dogs produce allergenic molecules, regardless of their breed. But it is true that some breeds are less likely to cause allergic reactions than others. These so-called 'hypoallergenic' breeds include the poodle, bichon frise, schnauzer and Irish water spaniel.

What should you do if your dog suffers from allergies?

If you suspect your dog is allergic to something, it's important to take the right approach and seek veterinary advice.

  1. Consult a vet. That's the priority! Take your dog to the vet, who will carry out a clinical examination. They'll help you determine whether it's really a case of allergy and what's causing it.

  2. Adjust their lifestyle. If your dog does have an allergy, you may need to adapt their lifestyle: their diet if it's a food allergy, their route or time of walk if it's a pollen allergy, etc.

  3. Give them medication. In some cases, your vet may recommend antihistamines or corticosteroids in tablet form.

Spotlight on our specialist editor, Marie-Adine Bories

Marie-Adine is a naturopath and a graduate of the Institut de Naturopathie Humaniste. For several years now, she has been helping her customers to be proactive about their own health by creating personalised, educational programmes. Passionate about our emotions and their impact on our ability to heal, she teaches a range of health techniques to help us manage stress, improve sleep and boost vitality.