The symptoms of pet allergy
Symptoms last all year round and include blocked, runny, itchy nose and sneezing. Affected individuals often say they feel as if they have a perpetual cold. The condition is actually known as perennial rhinitis. Contact with animals can also make people with asthma feel worse. Those who keep animals may have continuous asthma as a result, whereas people who do not keep animals themselves may find that visiting a home that contains animals triggers wheezing.

Cat Allergy
Allergy to cats is the commonest problem in adults. This is partly because cats are very common and partly because cats are very clean. The main cat allergen comes from saliva and hair glands. It is spread all over the fur as the cat washes and then dries. This powder (dander) is very fine which means that it floats in the air very easily and stays airborne. Cat allergen levels adequate to trigger asthma will be present throughout the room within 5 minutes of a cat entering and can then remain suspended in the air for many hours. Breathing in this dander is responsible for causing your allergic symptoms.
Beds and other places become impregnated with cat allergen. It can even contaminate the clothes of someone who has merely visited a house with cats and can also be carried into a household on second-hand furniture. Cat dander is very persistent. It can be found in dust up to a year after the cat has been removed from the house. For this reason, people sometimes develop allergic symptoms when they move house to a home where a cat previously lived.
Families with allergic members are advised against having cats in the home. If you decide to get rid of your cat, the allergen levels will take approximately 12-16 weeks to reduce if thorough cleaning is employed. If you have a cat and can’t bear to part with it, try to keep it away from beds and soft furnishings, although that is easier said than done. Recent studies have also shown that cats shed less allergen if washed weekly. This does, however, need to be combined with thorough cleaning and vacuuming throughout the home to minimise allergen levels.

Dog Allergy
As with cats, it is the dander that causes allergic problems. Dander is produced from saliva, hair and skin scales. Although there are about as many dogs as cats in the UK, allergy to dogs is less common because dog dander particles are larger and therefore less likely to be inhaled; moreover, dog allergens break down much more quickly than those of cats.
All dogs produce dander, therefore reported differences in sensitivity to different dog breeds probably relates more to the level of exposure. Some reports do describe hair length as important. It is possible however that longer hair may harbour other allergens such as dust mite, pollens and moulds to which an individual may also be sensitive. It is also necessary to note that dogs with skin conditions such as flea allergy or eczema are more likely to have increased dander production. Poor nutrition, poor general health, hormonal factors and even environmental influences may also contribute to increased dander production.
As with cats – if you are allergic to dogs, we advise against having a dog in the home. An alternative may be to limit the dog access; keeping it outside and/or in the kitchen area only. This, however, is not ideal because the allergen will still be spread around the house by the rest of the family.
Commercial agents designed to “cleanse” the dog and remove antigens such as dander, so far have not been proved to be clinically effective.

Other pets
Most other domestic animals can cause allergies but in order to become sensitised you have to be exposed to the animal for a while before you develop IgE antibodies (which make you allergic). Allergy to horses can be very troublesome and can be triggered both by direct contact with horses and by exposure to dried horse sweat and dander on the clothes of people who have been riding.
Allergy to small rodents is very common among people who work with laboratory animals, typically rats, mice and guinea pigs. The main source of rodent allergens is urine as it contains small amounts of protein which dry and are then inhaled when the bedding is disturbed. When these animals are kept as pets, sensitisation can easily occur. They should not be kept in the bedrooms of children with other allergies.
Pigeons and budgerigars appear to be the most troublesome of birds. Feathers and droppings can both be responsible for causing allergic problems.

General advice
If you do not currently have a pet, think carefully before you buy one. This is especially true if you have a family history of asthma/allergies; even if you are not currently allergic to animals, you may become sensitised and, consequently, allergic when repeatedly exposed to the pet. Consider a pet that does not shed allergen, such as fish. Alternatively, why not adopt an animal at your local zoo or wildlife park?