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Ever come into the proximity of a cat and suddenly started sneezing and your eyes began swelling up? Well you may be allergic to cats! What a travesty! But what causes cat allergies exactly? People have long held the belief that it was a cat’s hair that made them allergic. However, it is in fact a protein your cat produces called Felis Domesticus 1 (Fel D1) which is the culprit! We investigate why this is the case.

First of all, let’s have a quick overview of a person’s immune system when they suffer an allergic reaction.  If a person whose body’s immune system considers an allergen (i.e. pet dander, pollen) they come into contact with as an ‘invader’, the body reacts by producing an antibody called immunologbulin E (IgE). IgE adheres to other immune cells (i.e. basophils and mast cells) which, in turn, makes them release inflammatory chemicals such as histamines. These chemicals causes the symptoms one would normally associate with allergies such as asthma, wheezing and increased nasal discharge.  

For people allergic to cats, Felis Domesticus 1 (Fel D1), is the allergen responsible for triggering the reaction. Fel D1 is a protein that is secreted by your cat’s sebaceous glands in their skin and found in your cats’ saliva and urine. When Fel D1 is secreted it becomes mainly attached to dead skin cells, commonly referred to as cat dander, on your cat. Like humans, cats shed their dander continuously which enables the Fel D1 to spread easily throughout the furniture, beds, carpets in the house (and outdoors). What makes matters worse is that cat dander can remain airborne for up to several hours which allows Fel D1 to proliferate into other areas (schools, office buildings etc) where cats do not normally reside. Furthermore, considering cats love to groom themselves by licking, they can transfer Fel D1 to their fur as well! Double whammy!!

Pondering if you are allergic to cats? These list of symptoms may assist you:

  • Difficulty breathing i.e. wheezing, asthma
  • Rashes
  • Sneezing constantly
  • Frequent nasal discharge
  • Swollen, watery, itchy, red eyes 

What is interesting is that people who are allergic to cats have never actually owned a cat themselves! On initial encounter with Fel D1, most people do not evoke a reaction. It can take a steady period of time (several years) before they develop the allergy. If you are one of the poor unfortunates who suffer from cat allergies, here are a few ways to reduce the presence of Fel D1 in the home:


  • It is recommended to desex your cat. Studies have shown that non desexed male cats produce higher levels of Fel D1 than neutered ones. You may even consider owning a female cat as they also produce lower levels of Fel D1 as well. 
  • There are reports that darker coloured cats secrete higher levels of Fel D1 than lighter coloured cats. This is inconclusive at present but it doesn’t hurt if you are thinking of adopting a cat. 
  • If you have carpeting in your place, it is better to replace them with floorboards or tiles. If this is not a possibility (and it can be very expensive to carry out no doubt), ensure that you clean the carpet regularly via vacuum and steam clean.
  • HEPA filters can reduce the level of Cat Dander in the air. Less Cat Dander means less Fel D1! Regularly clean HEPA filters with a vacuum cleaner as well.
  • Prevent your cat from having access to bedrooms by ensuring the bedroom door is closed at all times. 
  • Place kitty litter trays in a remote location of the house such as an indoor garage or laundry area.
  • Wash your clothes at the highest possible setting if you feel you have come into contact with cat dander.
  • Wash your cat regularly to deplete levels of cat dander. Although this can be risky business if your cat is not fond of baths and prefers to scratch you furiously instead.

If you have any questions about cat allergies definitely contact us here at the Concord Veterinary Clinic and we will be happy to assist you!