Fel d 1

Timmy - unneutered males are more prone to causing an allergic reaction.
 Photo: MikeB

Fel d 1 stands for Felis domesticus allergen 1. It is also referred to sometimes as "cat dander". Domestic cats are one of the most important sources of allergic disease in the western world with about 10% of people allergic to cats.

The allergen is in the cat's saliva (and therefore on the fur) and secreted from perianal and lachrymal glands.

The allergic reaction can be mild (e.g. itching) or life threatening (severe asthma). Cat allergens are very common and difficult to avoid. An allergen is a substance (a non-parasitic antigen) that produces an immune response. The immune response is the production of Immunoglobulin E (IgE) an antibody. Its role is unclear but the response is inappropriate and causes allergic reaction such as sneezing and asthma.

Life Style Pets Inc (Allerca cats) claim to have modified the gene responsible for the production of the allergen in the domestic cats they breed (or are bred by affiliated cat breeders) thereby eliminating the allergic reaction. They don't explain themselves however.

Some cat breeds are said to be "hypoallergenic" meaning they don't cause the same degree of allergic reaction. Claims have been made for several breeds. Generally these are unsubstantiated. Savannah cats can also be hypoallergenic. But to be honest no cat, not even the hairless cats are hypoallergenic to any substantial degree. 

For the first time I have become allergic to a cat (only slightly though). He is a stray who comes in for food and rest. When I touch him, within about a minute I itch on the hand, head, legs for example. The itching need not be where I made contact with him. In fact I only have to look at him to start itching. This is because his dander is in the room.

I wash immediately after stroking him. I even kiss him sometimes, because my tenderness towards him outweighs the inconvenience of the allergic reaction. He is unneutered and unneutered males are the most likely to have a strong dose of Fel D 1 in their saliva.

Photo of Timmy the stray cat referred to in this post. He's crashed out on my chair having eaten three or four sachets of prime cat food.

Update: Purina have made LiveClear (see above) a dry cat food that has been found to be successful in reducing their potency of the allergen. Look it up if you are allergic to cats.

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