Asthma, Allergies and Pets

Pets May Cause Havoc for Allergic and Asthmatic Patients
Keeping domestic animals as household pets is a universal activity. Pets provide companionship, security and a sense of comfort. Children often learn responsibility and lessons about life and death from pets. However, people with allergies should be cautious in deciding what type of animal can safely be brought into their home.

Pets can cause problems to allergic patients in several ways. Their dander (skin flakes) can cause an allergic reaction, as well as their saliva and urine. The animal hair itself is not considered to be a very significant allergen. However, the hair or fur can collect pollen, dust, mold, and other allergens.

The best types of pets for an allergic patient are tropical fish, snakes, lizards, turtles, salamanders, ants and certain types of insects, frogs, spiders and tortoises. All of these pets do not shed dander, have hair or fur, nor does their excrements create allergic problems. However, patients should keep in mind that large aquariums can add to the amount of water vapor in a room, thus increasing mold and house dust mite concentrations in their home.

Most Common Pets
The most common household pets are dogs, cats, birds, hamsters, rabbits, mice, rats and guinea pigs. Larger animals such as horses, goats, cows, chickens, ducks and geese, even though kept outdoors, can also cause problems if kept as pets. It is estimated that 25% of children are exposed to horses either by riding them or by being in their barns or pens.
The number of pets in the United States is estimated at more than 100,000,000. This large number also increased the likelihood of accidental exposure to animals by the allergic patient when visiting homes, farms, etc.

Both feathers and the droppings from birds, another common pet, can increase the allergen exposure. The allergic patient should not sue feather pillows or down comforters. If a feather pillow is used, it should be placed in a plastic encasing. An encasing with a zipper is recommended, so none of the feathers can escape.

Bird Droppings
Bird droppings can be a source of bacteria, dust, fungi and mold. This also applies to the droppings of other caged pets, such as gerbils, hamsters and mice. The ideal situation for an allergic patient would be to have no pet at all. However, many pet owners feel strongly about their pets, and would rather remove the allergic individual from the home than the pet! A pet such as a dog or cat should, at the very least, be kept out of the allergic patient’s bedroom.

The avid pet owner may claim that exposure to his or her pet does not cause them any problems. This, however, should be viewed skeptically, since pet ownership is an emotionally-charged subject. Also, may allergic pet owners are rarely away from their pets, so an accurate reporting of pet-related symptoms may not be possible.

Testing to determine an allergy to animals is not always accurate. Skin tests or radioallergosorbent tests (a blood test for allergens) can give a “false” negative reaction. To gain confirmation about a pet’s significance as an allergen, the pet should be removed from the home for several weeks and a thorough cleaning done to removed the hair and dander. It should be understood that it can take weeks of meticulous cleaning to remove all the animal hair and dander before a change in the allergic patient is noted.

A frequently mistaken idea is that short-haired animals cause fewer problems. It is the dander (flakes of skin) that cause the most significant allergic reactions, not the length or amount of hair on the pet. As stated previously, allergens are also found in the pet’s saliva and urine. In addition, dogs have been reported to cause acute symptoms of allergic conjunctivitis (inflammation of the eye) and hay fever after running through fields and then coming back in to contact with their owners.

Severe Reactions
Some allergic patients may have severe reactions (wheezing and shortness of breath) after exposure to such pets as cats, rats, horses and guinea pigs. Also, a chronic, slowly progressive feeling of shortness of breath, loss of energy and feeling of fatigue can result from long-term exposure to birds and their droppings. This type of disease is known as hypersensitivity pneumonitis and can result in severe disability. In the event of these severe cases, removal of the offending animal is mandatory.

In summary, pets can cause direct and indirect allergic problems, both from the dander and from pollen accumulated on the fur. Allergic children and adults should not pet, hug or kiss
their pets, because of the allergens on the animal’s fur or saliva. Those pets that are known to cause allergic reactions should be removed from the home of the allergic patient. If the family is unwilling to do this, the pet should be kept out of the patient’s bedroom and, if possible, outdoors.

Limit Pets to Few Rooms
Indoor pets should be restricted to few rooms in the home if possible. Isolating the pet to one room, however, will not limit the allergens to that room. Air currents from forced-air heating and air-conditioning will spread the allergens throughout the house. Homes with forced-air heating and/or air-conditioning may be fitted with a central air cleaner. This may remove significant amount of pet allergens from the home. The air cleaner should be used at least four hours per day.

Text developed by ACAAI members: Gerald L. Klein, M.D., Robert W. Ziering, M.D., Vista, CA.