By Nick Gromicko and Rob London
Cats and dogs produce allergens
that pose a health threat to certain individuals.

Modes of Transmission
Cat dander consists of microscopic
pieces of cat skin that have dried, flaked off and become airborne. Shed dander can land on and stick to bedding, curtains,
carpeting, and other surfaces, including people's skin and clothing. It contains Fel D1, a glycoprotein found in the
cat's sebaceous glands, located under their skin, and, to a lesser extent, it is found in cats' saliva and urine. Fel D1 can
cause rapid allergic reactions in sensitive individuals. Unlike cats, the dogs’ allergen, Can F1, is found in higher
concentrations in their saliva than in their sebaceous glands.
Facts and Figures
- More people are allergic to cats than they are to dogs. This may be due to the
severity of the allergen Fe D1, or because dogs are generally bathed regularly, whereas cats are not.
- Between 6 and 10 million Americans are allergic to cats, and approximately one-third of them have cats in their homes.
- Animal dander, hair, and other organic debris in homes can also result in a significant increase
in the level of dust mites, mite feces and other allergenic insect parts.
- Allergens may be found
months or years after a pet has been removed from a house.
- Pet-borne allergens commonly
infiltrate places where pets have never been present, such as schools, workplaces, and other public spaces. Since dander allergens
are sticky, they can be transported to these places on the clothing of pet owners.
- Animal
hair, despite popular belief, is not considered to be a significant allergen. However, hair can collect pollen, dust, mold,
and other allergens.
- There are no "non-allergenic" breeds of dogs or cats. Some breeds of
both species, however, are believed to be hypoallergenic; anecdotal reports claim that the Siberian, rex and sphinx cat breeds
are less likely to provoke an allergic attack than most other cats. Similarly, dog breeds, such as poodles and schnauzers,
have been reported to be less allergenic. None of these claims has been validated scientifically.

Cat and Dog Allergy Symptoms
These include:
- itching;
- sneezing and congestion;
- redness, itching, swelling
and watering of the eyes;
- post-nasal drip, itching or hoarseness, and the need to clear the throat often;
- itchy rashes or hives;
- itching, plugging or popping in the ears; and
- coughing, wheezing, tightness in the chest, frequent bronchitis, and a shortness of breath.
How to Test If a Cat or Dog Has Been in a Building
Pets are forbidden by many lease agreements, which may then be
violated by tenants who secretly house cats or dogs. Also, cats may visit a residence at night to forage for food or gain
shelter. The following detection methods may be used:
- Smell for the animal. If the cat is an indoor cat, a litter box must have been used somewhere in
the building, and they almost always produce an odor. Even after they are removed, the smell from a litter box may linger
for quite some time. If a male cat was present in the building and he has urinated on or "marked" any areas, the odor
will be very strong.
- Look for hair. Somewhere in the building, especially where the cat likes to sleep
or rest, there will be large amounts of hair.
· Use a blacklight to check for pet urine.
Cleaning Tips for Buildings
Previously Occupied by Cats and Dogs
Inspectors may be asked about pet-allergen cleanup by clients who are looking to
buy a home but are concerned about the air quality in their prospective new home. The following suggestions may be offered:
- Obtain a thorough, professional
duct cleaning.
- Commercially steam-clean, professionally dry-clean, or use very hot water to launder clothing.
- Wash and use a HEPA vacuum for interior surfaces. Note that ordinary vacuum cleaners, which cause allergenic particles
to become airborne, are ineffective and may even worsen the problem for sensitive occupants.
Advice
for Clients with Pets
A combination of approaches—medical control of symptoms, good housecleaning and planning—is
most likely to succeed in allowing an allergic person to live with pets. For allergic clients who won’t give up their
pets, inspectors can pass on the following tips:
- Take allergy medication. Most fall under one of the following three categories:
- antihistamines,
such as over-the-counter Claritin or Benadryl, or the prescription drugs Allegra or Zyrtec;
- decongestants,
such as OTC Sudafed or prescription Allegra-D; or
- prescription steroids, such as Flonase
or Nasonex sprays.

- Get allergy shots. These are not always effective, however, and completing treatment can
take years.
- Bathe your pet on a weekly basis. Cats can get used to being bathed, but it’s critical to only use
products labeled for them.
- Keep the pet outdoors as much as possible.
- Allergic individuals
should not hug, pet or kiss their pets.
- Have your pet spayed or neutered. The allergen produced by a
cat is highest in unaltered males and lowest in altered males.
- Remove clothing worn after grooming
or playing with pets.
- Litter boxes should be placed in an area unconnected to the air supply to
the rest of the home, and should be avoided by allergic individuals.
- Design a cleaning regimen
that can substantially reduce those levels, ranging from discarding materials to HEPA-vacuuming to washing certain surfaces.
- Maintain adequate ventilation.
- Remove as much carpet from the home as is
feasible. The less dander-catching furnishings, such as cloth curtains and blinds, the better.
- Clean
frequently and thoroughly to remove dust and dander, washing articles such as couch covers and pillows, curtains and pet beds.
- Create an "allergy-free" zone in your home—preferably, the allergic person's bedroom—and
strictly prohibit the pet's access to it. Consider using impermeable covers for the mattress and pillows.
·
Keep pets off furniture, especially
upholstered furniture where dander can be easily transferred.
In summary, irritation and contamination
caused by pet allergens can be limited by proper care of their hygiene, homes and owners.
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International Association of Certified Home Inspectors, Inc.