I would like to share some supportive information we give to people who suffer from cat allergies as many are unaware that "all" cats regardless of breed or if long, short or no hair breed of cats can cause allergies. Any vet can confirm this fact. Older books on cats and cat care usually blame the allergy on cat fur e.g. breathing in small particles of the fur itself. Some blame it specifically on the cat’s guard hairs (the long hairs within the cat’s coat) and may recommend keeping a breed which lacks these guard hairs e.g. Devon/Cornish Rex or the hairless Sphynx. Referring to these breeds as hypoallergenic or allergen-free is incorrect as It is not the hair which causes the allergic reaction. The real culprit appears to be a glycoprotein, Fel d1 which is secreted by the sebaceous glands and is the major cat allergen. This allergen is found in the fur, pelt, saliva, serum, urine, mucous, salivary glands, and hair roots of the cat. The main sources of the allergen, however, are the skin and saliva. When a cat grooms/washes itself, saliva is deposited on its fur (or skin in the case of hairless cats). The saliva dries into dust (dander or dandruff) which is released airborne when a cat scratches or moves and when humans stroke or brush a cat. Fel d1. All cats groom themselves, even those which lack guard hairs or which lack hair altogether (e.g. Sphynx). The dust forms on all types of cat hair or directly on the cat’s skin if it lacks fur. Hairless Sphynx cats produce dandruff directly on their skin and though they produce less of it than furred cats, they can still produce enough to trigger an allergic reaction. An allergy occurs when the body over-reacts to a substance (allergen) and produces excessive amounts of histamine. Excessive histamine production leads to the irritating symptoms associated with cat-allergy - itchy eyes, sneezing, skin rash etc. Although Fel d1 is the protein most often associated with allergies, humans are very variable and there will be some people who develop allergies to other feline proteins. Some people are unaffected by Siamese cats, but allergic to other cats and some people have reported whose cat alergy is only triggered by male cats (even if the cats are neutered). Anyhow, please consider reading the following website literature to learn more about the Fel d1 protein and how it affects allergies in humans. http://allergies.about.com/od/allergies1... http://www.allergysa.org/pet.htm#cat Here's a video (located on the webpage on the right side) by a veterinarian about the allergen Fel d1 and how it affects cat allergy sufferers. It's an organization who is is selectively breeding cats without the Fel d1 protein to make available for sale for those who who suffer allergies but would like to own a cat: http://www.allerca.com/ Additionally, some people find they are not allergic to kittens when they get them, however when the cats become adults they develop more allergies as a result.

The short answer is that none of them really are. Cat dander is made up of skin cells, and every cat has skin, even if they don't have fur. A full course of allergy shots taken over months or years, however long the prescribed treatment is for each person, can greatly reduce or alleviate the allergy symptoms.