Hypoallergenic is a term coined by advertisers (based on the Greek prefix hypo meaning "below normal" or "slightly") and first used in a cosmetics campaign in 1953. It is used to describe items (especially cosmetics and textiles) that cause or are claimed to cause fewer allergic reactions. Hypoallergenic pets still produce allergens, but because of their coat type or absence of fur or absence of a gene that produces a certain protein, typically produce fewer allergens than others of the same species. People with severe allergies and asthma may still be affected by a hypoallergenic pet.
Note that the term lacks a medical definition, but it is in common usage and found in most standard English dictionaries. In some countries, there are allergy interest groups that provide manufacturers with a certification procedure including tests that ensure a product is unlikely to cause an allergic reaction, but such products are usually described and labeled using other but similar terms. So far, public authorities in no country provide an official certification that an item must undergo before being described as hypoallergenic. The cosmetic industry has been trying for years to establish an industry standard for use of the term.
For allergy sufferers, a hypoallergenic pet might enable them to have a pet in their home, whereas most dogs, cats, rabbits, and other fur-bearing animals can make their lives miserable. The proteins that cause allergies are found not only in the animals' fur or hair but also in saliva, urine, mucous, and hair roots and in the dander sloughed from the animals' skin.
Some dog breeds have been promoted as hypoallergenic, such as the Afghan Hound and the Yorkshire Terrier whose coat (hair) does not shed and is the same pH as human hair creating no dander, Bolognese, Barbet, Maltese, Bichon Frisé, Shih Tzu, West Highland White Terrier, Poodle, Soft-Coated Wheaten Terrier, and the Schnauzer, and Portuguese Water Dogs are sometimes good choices for those who have allergies, because some of these dogs do not shed their hair or shed very little. However, no canine is known to be completely nonallergenic.
Cat breeds such as the Sphinx, Devon Rex and Cornish Rex, which lack some or all of the normal layers in cats' fur, are believed by mild allergy sufferers to be significantly less likely to provoke an allergic reaction than other breeds. Siberian cats and Russian Blue are also believed by some to have such properties.
A company called Allerca recently claimed to be able to produce a so-called hypoallergenic cat using gene silencing, but it has now instead used traditional breeding methods, starting with cats that naturally lack the gene that produces the glycoprotein Fel d 1 causing an allergic reaction in some people. However, no peer-reviewed studies have confirmed the company's claims and some scientists are skeptical of the company's assertions. Allerca is currently accepting orders for hypoallergenic kittens. Another company, Felix Pets, also claims to be developing a breed of hypoallergenic cat.
There is only one known hypoallergenic horse breed. The Bashkir Curly horse has a uniquely textured coat that lacks the protein (present in all other horse fur) believed to be the source of allergic reactions to equines. Many people with severe allergies to horses can handle Bashkir Curlies with no reaction.