All things cat allergy – debunking the myths and a breakthrough in managing allergens

People are allergic to many things… But did you know that as many as 1 in 5 adults have an allergic response to cats? And, that allergies to cats are the most common animal-origin allergies in humans?

Some people will be mildly affected, feeling itchy, snuffly or sneezing; others have severe skin reactions, and a few may even experience a serious asthma attack.

Today, to mark #InternationalCatDay, we’re covering all things cat allergy – starting with the debunking of the most common myths and finishing with exciting new research that could revolutionise how humans deal with cat allergies…

1. Cat hair causes allergies to cats
Cat hair is not the cause of allergies to cats 
Cats produce proteins in their salivary and sebaceous (skin) glands. These proteins are spread throughout a cat’s coat and skin during grooming. One of these proteins, Fel d1, is usually the allergen that people react to if they are allergic to cats. Fel d1 is released into the environment on dried flakes of skin (dander) and hair that is shed. So, although the cat’s hair can carry allergens, the hair itself is not the cause of a person’s allergy to cats.

2. Allergen-free or “hypoallergenic” cats exist 
There are no allergen-free or "hypoallergenic" cats
All cats produce Fel d1. However, the amount of Fel d1 produced by an individual can vary during the year, and different cats produce different amounts. Even hairless breeds of cats produce Fel d1, as the protein is produced in salivary and sebaceous (skin) glands of the cat. All cats groom and produce dander, which is then spread (with Fel d1) into the environment.

3. Hair colour and length influences allergen production 
Hair colour and length have no influence on allergen production
It was previously thought that cats with darker coloured hair and those with longer hair are more likely to trigger allergies than cats with lighter coloured or shorter hair. However, studies have shown that hair colour and length have no influence on Fel d1 production in cats.

4. The sex of a cat influences allergen production 
The sex of a cat doesn’t fully influence allergen production
Studies have shown that unneutered male cats generally produce higher levels of Fel d1 than neutered male cats and both unneutered and neutered female cats. However, each cat’s level of Fel d1 varies based on genetics, so an intact male cat could potentially produce less Fel d1 than a high-producing female or neutered male cat.

Could cat food hold the answer to managing human allergies to cats?

Pet-food manufacturer Purina has released new research that could revolutionise how humans deal with cat allergies

The research, published in our veterinary division the International Society of Feline Medicine's Journal of Feline Medicine and Surgery (JFMS), found that feeding cats an antibody (IgY) can significantly reduce the active levels of the major cat allergen, Fel d1, at its source in cats' saliva.

During the study, 105 cats were fed a diet containing IgY for 10 weeks – leading to a 47% drop (on average) in the amount of active Fel d1 protein on the cats' hair.

Decreasing active Fel d1 on a cat's hair can reduce cat allergens shed into the environment on hair and dander. Reducing the allergen load in the environment has been shown to be beneficial to allergen-sensitive people. This is supported by preliminary findings from a small pilot study where 11 people with cat allergies had a reduction in symptoms when exposed to cats on the antibody diet compared to cats fed a control diet.

In cats, the antibody to Fel d1 has its effect in the mouth, neutralizing the protein in saliva, says Ebenezer Satyaraj, director of molecular nutrition at Purina. This way, the antibody disables Fel d1 “after its production by the cat, but before it spreads to the cat’s hair and dander — and before a response occurs in an individual sensitized to cat allergens,” says Satyaraj, who is leading the cat allergen research.

Since the role of Fel d1 in cat physiology is unknown, this approach doesn’t interfere with the normal production of Fel d1 by the cat, Satyaraj says. So far, he adds, safety tests have found no harm to cats fed the antibody.

Products containing the antibody are not yet available from Purina, but further research to determine its effectiveness for reducing cat allergens is planned. Although additional research is needed, these findings show promise for an alternative approach to the management of allergies to cats and we will keep you updated on any new developments.

In the meantime, for more information about this research and the Purina Institute, please visit:

For more information on allergies to cats please see our advice page:

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