© by aha! Swiss Allergy Centre - Info on allergies - animal allergy - Child is looking a cat outside of the window

Domestic animals have lived alongside mankind for millennia. Their status has changed dramatically over the decades. While they used to serve mainly as livestock in the past, were used for work and hunting and played a key role in the human diet, nowadays they are not uncommonly seen as a family member or a dear companion.

Causes and triggers of an animal allergy

Most cases of sensitisation are to cats, dogs, horses and rodents. As a result of closer contact with domestic animals, the risk of developing an allergy to those animals increases. Allergic reactions to cats are more common than to dogs, although the reason why that might be is still unexplained. Cat allergens are found to a varying degree with all breeds of cat. The antigen is mainly secreted in the saliva, in the sebaceous glands and from the skin cells and is spread by the cat licking its fur (which is why we often talk of an "animal hair allergy"). Female cats and castrated males secrete fewer allergens than non-castrated tomcats. However, most people also react to castrated tomcats and females. The main allergen from dogs is predominantly found in the fur and saliva. The allergenic burden for sufferers varies, depending on the breed of cat or dog. Generally speaking, short-haired dogs are known to produce more allergens than long-haired ones.

Allergens from house pets, like other airborne allergens as well, bind to dust particles and, depending on the size of those particles, float around in the air for hours until they fall to the ground. Animal allergens stick to people’s hair and clothing so that they are transferred to the air in localities where animals do not normally reside. This explains why high concentrations of animal allergens can be detected in school rooms and hotel rooms, cinemas and forms of public transport, for instance. As a result, people can have an allergic reaction without an animal actually being in the room.

Symptoms of an animal allergy

Allergy symptoms can be manifest as follows: runny nose, conjunctivitis (inflammation of the conjunctiva of the eyes), severe asthma. A shock reaction may even occur in isolated cases. Scratches from cats and dogs can lead to allergic skin irritation and swelling. 

Diagnosis and differential diagnosis

People who suspect they may be allergic to an animal, based on their own observations, can have this investigated by a doctor by means of skin and blood tests.

Therapy and treatment

As with all allergic diseases, avoidance of the allergen is the most effective therapy. If this is not possible, drug therapy is usually required. People with a severe animal allergy, which massively impairs their quality of life, may consider the possibility of specific immunotherapy. For the best possible result, the animal should ideally be relocated or given away before the therapy.

Tips and tricks

A lot of people do not realize they suffer from an allergy to their dear companion until after they have acquired a pet. There is usually a very strong emotional bond, which means giving up the pet is out of the question.
You can reduce your personal allergen burden by taking the following measures:

  • Keep animals outside the home, if possible.
  • Do not let the animal into sleeping areas.
  • Wash your hands after any animal contact.
  • Clean clothes with a clothes roller (do not use clothes brushes).
  • Delegate cleaning of animals’ resting and feeding areas to other family members.
  • Use washable covers for upholstered furniture and seating.
  • Remove carpets and other "dust traps".
  • Vacuum clean regularly: use a cleaner with  HEPA filter level 11 and allergen-proof casing.
  • Wet mop floors on a daily basis.
  • Use an air purifier with HEPA filter level 11.

Despite these measures, the starting point of the disease symptoms remains, namely the animal allergen. Animal hairs spread throughout the home, stick to clothing and other textiles.

Before acquiring a furred or feathered animal, allergy sufferers should consider a possible animal allergy with all its consequences (long-term treatment or having to give away the  beloved pet).

Facts and figures

If a person suffers from asthma, it is inadvisable to get a furred or feathered pet. Animals generally cause more dirt and dust in the home, which can have an adverse effect on the lung function of those affected. Animal hairs in themselves are an added irritation to the airways.

Given the current state of knowledge, it can neither be proved nor ruled out that growing up with a pet can have a protective effect against developing allergies.

Editors: aha! Swiss Allergy Centre in co-operation with the Scientific Advisory Board. For prevalence figures, see source references.

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