Animal or pet allergens found in buildings and indoor air quality:

This article outlines the basic indoor air quality and asthma-related concerns from animal allergens (dogs, cats, other animals), recommends actions, and cites authoritative sources for more in-depth reading. According to the US EPA and other expert sources, [paraphrasing document cited below] animal skin flakes, urine, feces, saliva, and hair can trigger asthma or other allergic reactions.

Dogs, cats, rodents and other mammals can trigger asthma/allergic reaction in people who have an allergy to animal dander. Proteins in these materials have been reported to sensitize people and can cause allergic reactions or can trigger asthma episodes in people who are already sensitive to animal allergens.

Photo above: Pippin the kitten resting on Katie the author's golden retriever. Katie served as Pippin's surrogate mama. [Click to enlarge any image]

The most effective method to control animal allergens is to remove the animal from the building, followed by thorough [professional] cleaning. I also discuss the effectiveness of various strategies for keeping your pet in a home with someone who has asthma or pet allergies.

Persistence of Animal Allergens & Animal Dander or Animal Hair in the Indoor Environment

Animal dander in homes is a common source of respiratory irritants associated with asthma and allergies.

Consider that dogs and cats are the most popular pet-companion animals in the world and that these two animal families are the source of very potent allergenic particles, specifically: dog dander and cat dander.

Animal dander, hair, and other organic debris in homes can also result in a significant increase in the level of dust mites, mite fecals, and other allergenic insect parts and fragments.

These two lab photos of human skin cells, animal skin cells (dander), and other debris are typical of a home where pets have been resident. The left photo includes a feather barbule fragment and insect fecals. The right photo shows skin cells and animal dander.

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Animal & dust mite allergen levels versus risk to people with allergies and asthmal.

Pet allergen removal: cleaning suggestions for buildings previously occupied by animals/pets - pet pet dander, pet hair, saliva, other materials. Allergy drug medication vs. Building cleanup as treatment for asthma reaction to animals indoors.

Animal dander study: animal dander advice: environmental study report text. Pets as family members - can I keep my pet but reduce indoor allergens?

How to reduce animal allergens indoors.

Article Contents

• PET ALLERGENS / PET DANDER - CONTENTS: Persistence of Animal Allergens & Animal Dander or Animal Hair in the Indoor Environment
  • PET ALLERGEN REMOVAL
  • ALLERGY DRUG MEDICATION VS. BUILDING CLEANUP
  • ANIMAL DANDER HAZARD LEVELS
  • PETS AS FAMILY MEMBERS
  • HOW TO REDUCE ANIMAL ALLERGENS INDOORS

Signs of "hidden" animal presence

We often find evidence of other animals who have been frequently present in a home even though the human occupants didn't know it - either because the animal was the pet of a prior owner (Chinchilla hair above) or a nocturnal visitor to the food bins (mouse hair below).

Finding evidence of animals might mean that additional cleaning is needed to remove their remaining allergenic particles.

The U.S. EPA indicates that allergens are found months after a pet (or mouse problem) has been removed.

Our particle studies in homes with pets show that although a dog or cat who is never allowed out of the basement will concentrate its hair and dander at that level, I will find the animal dander and hair at all floors and in every room of the home.

We often find significant levels of allergens in buildings where the source animal(s) have been gone for years if professional cleaning has not been performed.

Even when cleaning is thorough I can find allergen materials remaining. In fact, I find some levels of animal dander in most homes, even if the home has never housed a pet, and in homes where a previous owner had pets, the dog or cat dander is often among the most frequent particles found in our samples.

While careful and thorough cleaning after animal removal is usually successful at removing the bulk of allergenic particles, for people who are extremely sensitive even low remaining allergen levels may be a problem, particularly if stirred or distributed by non-HEPA vacuuming and dusting, by the operation of HVAC equipment, ceiling fans, whole house fans, or other sources of indoor air movement.

Pet Allergen Removal: Cleaning Suggestions For Buildings Previously Occupied by Animals/Pets

After removing the pet or pest animal(s), the following measures are recommended: thorough professional duct cleaning, commercial steam cleaning of some materials, dry-cleaning or very hot water laundering of clothing, freezing of small items (to kill dust mites), washing and HEPA vacuuming of interior surfaces. N

ote that ordinary vacuum cleaning is not effective and may make matters worse for sensitive occupants as it causes allergenic particles to become airborne.

Animal dander particles can be less than 1 micron in size and thus may remain airborne for more than 8 hours after vacuuming.

Many sources offer advice aimed at keeping a pet in the home: keeping pets out of bedrooms and other sleeping areas and keeping these areas isolated from pet-occupied areas, keeping pets away from fabric-covered furniture, frequent washing of pets, frequent house cleaning using the extensive means described above are all listed.

More suggestions for dealing with pet allergens in the home are in this document at the Recommended Articles list towards the end of this page.

Drug Medication vs. Building Cleanup as Treatment for Asthma Reaction to Animals Indoors

No expert sources other than drug suppliers cite using medication as the first choice in addressing pet allergies. On the other hand, most expert sources I surveyed agreed that "...the most effective method to control exposure to animal allergens is to keep your [building] pet [and animal-pest] free."

Animal Dander Hazard Levels & Animal Dander Advice

Environmental Studies of Animal Dander Hazard Levels

The following is our standard advice included in indoor air quality investigations when I find a high level of animal dander in a building, regardless of whether it's cat, dog, other pets, or other animals.

Animal Dander: According to the US EPA and other expert sources, [paraphrasing document cited below] animal skin flakes, urine, feces, saliva, and hair can trigger asthma or other allergic reactions. Dogs, cats, rodents and other mammals can trigger asthma/allergic reaction in people who have an allergy to animal dander.

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Notes to the table above

• Barnes, Kathleen C., and Mark C. Liu. "The role of genetics and indoor allergen exposure in atopic asthma." Asthma: Causes and Mechanisms of an Epidemic Inflammatory Disease. Boca Raton, Lewis (1999): 197-223.
• Bartholome, K., W. Kissler, H. Baer, E. Kopietz-Schulte, and U. Wahn. "Where does cat allergen 1 come from?." Journal of allergy and clinical immunology 76, no. 3 (1985): 503-506.
  Abstract:
  Cat allergen 1, the major allergen from cats, has been demonstrated to be present in surface washing and in saliva. With the use of an immunohistologic technique with monospecific anti-CA 1, we demonstrated two different sources of the protein, mucous salivary glands and hair roots, where it originates from sebaceous glands.
• Chapman, Martin D., Peter W. Heymann, Susan R. Wilkins, Martha J. Brown, and Thomas AE Platts-Mills. "Monoclonal immunoassay for major dust mite (Dermatophageides) allergens, Der p I and Der f I, and quantitative analysis of the allergen content of mite and house dust extracts." Journal of allergy and clinical immunology 80, no. 2 (1987): 184-194.
  
  Abstract:
  Monoclonal, two-site radioimmunoassays (RIAs) were developed to measure allergen Der p I of Dermatophagoides pteronyssinus or Der f I of D. farinae. Microtiter plates coated with monoclonal antibody (Mab) were incubated with mite extract, and bound allergen was detected with a second 125I-labeled Mab of different epitope specificity.
  
  The Mab RIAs were very sensitive (nanogram range) and highly specific. D. pteronyssinus extracts with different concentrations of Der p I demonstrated parallel binding curves, whereas a potent D. farinae extract demonstrated <5% of the Der p I binding in the same assay. Similar parallel curves were obtained with several D. farinae extracts in the Der f I assay, whereas D. pteronyssinus extract demonstrated little or no binding.
  
  The Mab RIAs were compared with an inhibition RIA that measured cross-reacting determinants on both Der p I and Der f I (antigen P1 equivalent [AgP1Eq].) The results demonstrated good quantitative agreement between these assays in commercial mite and house dust extracts (mean difference 1.57 ± 0.5-fold).
  
  Thirty house dust samples with known mite counts, Der p I, and AgP1Eq content were also compared. The summed Mab RIA values for Der p I and Der f I demonstrated a very good correlation with AgP1Eq values (r = 0.86; p < 0.001) and with assessments of total mite-allergen content by RAST inhibition (n = 21, r = 0.77; p < 0.001).
  
  Furthermore, in samples with more than 10 mites per 100 mg of dust, the Der p I:Der f I ratio closely correlated with the ratio of the two mites counted by microscopy (n = 15, r = 0.89; p < 0.001).
  
  The Mab RIAs can measure allergen levels in mite or dust extracts without the need for purified allergen or affinity-purified antibodies and can readily be standardized.
  
  These assays will be useful in epidemiologic studies of allergic asthma, to assess patients' exposure to mite allergens, and the effects of avoidance regimens. Because of the long-term stability and reproducibility of the reagents, Mab-based assays for specific allergens will also play an important role in the standardization of mite and other allergen extracts.
• Kern RA, Medical Clinics of NOrth America, 5,751, 1921
• Kern, Richard A. "XLVIII Some Practical Considerations concerning Respiratory Allergy." Annals of Otology, Rhinology & Laryngology 63, no. 3 (1954): 620-639.
• Lind P., Allergy, 41, 442, 1986
• Platts-Mills, Thomas AE. "Indoor allergens." Middleton’s allergy: principles and practice (2013): 453-469.
  
  Excerpt: The significance of house dust as an allergen was first recognized by Kern in 1921, when he reported that many patients with asthma or rhinitis exhibited positive wheal-and-flare skin responses to extracts of dust obtained from their own house (autologous dust).
• Platts-Mills, Thomas AE, and Martin D. Chapman. "Dust mites: immunology, allergic disease, and environmental control." Journal of Allergy and Clinical Immunology 80, no. 6 (1987): 755-775.
  
  Dust has been recognized as a trigger factor for asthma for many centuries. In 1921 Kern' demonstrated that extracts of house dust would produce a positive immediate skin test in many patients with asthma. This association between house dust sensitivity and asthma was confirmed, and treatment of asthma with injections of house dust extract to produce "desensitization" was widely practiced.
  
  It was also reported that many older children and adults with AD had positive immediate skin tests to house dust extracts.^ Although it was established that house dust contained a unique "atopen," in addition to the known allergens at that time,^ " its origin remained obscure until 1964 when Voorhorst et al.' suggested that the most important single source of house dust allergen was mites of the genus Dermatophagoides.
  
  These sightless eight-legged animals are —1/3 rmn long (i.e., not quite visible to the naked eye), feed on human skin scales, and are members of the order Acaridae (i.e., close relatives of ticks and spiders (Fig. 1).
  
  Voorhorst et al.* established that there was a good correlation between the allergenicity of house dust and the content of dust mites, that allergen levels increased when mites grew in dust, suggesting that the allergen was secreted or excreted, and that dust mites could be grown in the laboratory.
  
  The discovery of the optimal growth conditions for dust mites (i.e., 70° F and 70% relative humidity on human shavings) ...
• Platts-Mills TAE, de Weck Al, Journal of Allergy & CLinical Immunology, 83, 416, 1999
• Pratt, Henry N. "House dust hypersensitivity in perennial asthma of childhood." Journal of Allergy 8, no. 1 (1936): 60-65.
  Abstract:
  By means of intracutaneous tests and passive transfers it has been determined that approximately 79 per cent of children between the ages of one and twelve years who suffer from perennial asthma are skin sensitive to house dust extract and have reagins to this atopen in their serums.
  
  The frequency and severity of this sensitivity as evidenced by the magnitude of the skin test and passive transfer reaction increase with the advancing years of childhood.
• Randolph, Theron G. "House dust allergy." Archives of Otolaryngology 52, no. 1 (1950): 40-57.
  Abstract:
  THE GENERAL approach in handling house dust sensitivity has remained practically unchanged since the clinical importance of house dust as an allergen was appreciated by Cooke1 in 1918 and the subsequent and almost simultaneous publications of Vander Veer,2 Kern3 and Cooke4 in 1921 and 1922.
  
  The next milestone along this way was the development of superior methods of extracting and standardizing house dust extracts by Boatner and Efron5 in 1940.
  
  More recent contributions to the understanding of the house dust problem, particularly as it affected certain cases, was the emphasis on low dosage schedules by Hansel6 and the improved methods of specific diagnosis and treatment of inhalant allergy as recently worked out by Rinkel.7
• Voorhorst R. et al, Journal of Allergy , 39,325,1967

Proteins in these materials have been reported to sensitize people and can cause allergic reactions or can trigger asthma episodes in people who are already sensitive to animal allergens.

The most effective method to control animal allergens is to remove the animal from the building, followed by thorough [professional] cleaning. The EPA indicates that allergens are found months after a pet (or mouse problem) has been removed.

I often find significant levels of allergens in buildings where the source animal(s) have been gone for years if professional cleaning has not been performed. Even when cleaning is thorough I can find allergen materials remaining.

While adequate cleaning after animal removal is usually successful, for people who are extremely sensitive even low remaining allergen levels may be a problem, particularly if stirred or distributed by HVAC equipment or other sources of air movement.

After removing the pet or pest animal(s), the following measures are recommended: thorough professional duct cleaning, commercial steam cleaning of some materials, dry-cleaning or very hot water laundering of clothing, freezing of small items (to kill dust mites), washing and HEPA vacuuming of interior a surfaces.

Note that ordinary vacuum cleaning is not effective and may make matters worse for sensitive occupants as it causes allergenic particles to become airborne.

Animal dander particles can be less than 1 micron in size and thus may remain airborne for more than 8 hours after vacuuming.

Pets as Family Members: What to do If Your Pet is a Family Member

Some people with allergies and even asthma (and of course others without these complaints) have pets who have become such a loved family member that "getting the animal out of the house" is not something they're not willing to consider.

Some of our clients have taken this position and stuck with it until the sufferer's asthma became acute. When I was a boy, and was terribly allergic to cats, we had them in our home anyway.

We loved our cats and played with them constantly, with running eyes, sneezing, and a runny nose the whole time. Luckily for me it was a childhood allergy that I outgrew, or perhaps became immune-to.

Some remarkable studies have shown that living in a very sterile environment increases our vulnerability to some diseases and allergies. Farm kids who are exposed to enormously higher levels of allergens than city kids, have a much lower incidence of asthma. If you're allergic or asthmatic you should discuss these concerns with your doctor and should be candid about your exposure and your intentions regarding the pet.

Restricting a pet to only certain rooms or floors in a house might reduce the allergen level in some areas but it may not reduce it enough to alleviate suffering for anyone who is sensitized. Furthermore this is not the happiest life for a pet to live in the basement away from its family.

How to Reduce (somewhat) Exposure to Pet Allergens

What else can you do to reduce the indoor animal dander problem in a home with asthmatics or people with allergies? These suggestions are roughly in order of importance and effectiveness, in the author's opinion, with some consideration given to ease of implementation.

Frequent house cleaning including damp mopping or HEPA vacuuming will not cure this problem but will reduce the particle levels

Eliminate indoor carpeting.

In buildings with wall to wall floor carpeting or large area rugs, our indoor particle studies show that these floor coverings form an inexhaustible reservoir of allergens including the original animal dander from pets which no amount of vacuuming or "carpet cleaning" will remove completely.

Depending on the historic indoor moisture levels, quite often I also find that dust mite fecals, another very common indoor allergen, are at much higher levels in homes with pets. More pets or larger pets, shedding more dander and thus feeding more mites, produce higher levels of mite fecals in indoor dust.

HEPA vacuum cleaners,

especially units that do not have significant air leaks when the vacuum is running, do not stir up as much airborne debris, allergens and other particles, as ordinary vacuum cleaners. But before buying an expensive vacuum cleaner, further evaluation of the leakiness, operating cost, and bag or filter changing convenience should be made. I collect data on vacuum cleaner effectiveness but this work is not ready for release. When it is I'll post it at this website.

Central Vacuum Systems,

if properly installed, vent directly outside, avoiding the issue of stirring up indoor particles during house cleaning. It's a more-costly but great idea. Just be sure the vac is properly vented. I've inspected homes at which the central vacuum machine was in a laundry room or basement, venting its dust back into the home.

Humidity control:

is a step more critical than may be obvious. In homes with high humidity, of which the most egregious case is a carpeted damp or wet basement, the level of dust mite and other insect fecals (including carpet beetles and other mites) skyrockets. In homes with a high level of animal dander these animal skin cells form a feast for dust mites.

When we investigate the air and dust in buildings which have a combination of a high level of animal dander, carpeting, and high humidity, these three strikes against indoor air quality are a strikeout for asthmatics and people with allergies.

Keep the humidity low enough to discourage dust mites (45% to 55%, with a lower target for problem areas like basements and crawl spaces) and fix gutter/downspouts, plumbing leaks, or other sources of indoor moisture.

Also see INDOOR HUMIDITY LEVEL TARGET - to avoid a mold problem?

Air filtration by HVAC equipment can substantially reduce indoor airborne particle levels if the equipment is designed for that purpose, including cascaded air filtration and continuous fan operation.

More Reading: For a description of this approach, see Air Conditioning System Blower Fans & Filters CASCADING for Optimum Indoor Air Quality

Pet Care:

our cat sheds like crazy in the spring. Frequent brushing makes a difference in how much cat hair is distributed in the house. Also larger animals, particularly dogs, bring in a lot of dust and debris from outside, adding to the particle and possibly allergen indoor load - but then, this is arm-waving opinion, not science.

Air Purifiers:

none of the portable indoor air "purifiers" on the market (May 2006) is very effective at reducing the overall indoor airborne particle level in buildings, despite claims, and in some cases, poorly designed studies which may say otherwise.

I have measured dust and air in homes which in some cases had several such devices operating in each room.

There was no obvious correlation between use of this equipment and a reduction in indoor particle levels except when the equipment was operated in a small room which has its windows and doors kept shut, has no wall to wall carpeting, and has an absolute lack of clutter, leaving smooth, easily cleaned surfaces and little fabric, curtain, or other materials to act as particle reservoirs.

Ozone Generators:

a dog expert who sometimes boarded up to 15 dogs in her home spent a good part of her life cleaning. Nonetheless the level of dog dust and dander was astonishing, penetrating even the walls and attic of the building. After a decade of this craziness we didn't need IAQ instruments and surveys to see the layer of thick brown dust on the attic insulation and even in wall cavities around any penetration such as at electrical outlets.

The dog girl ran an ozone generator in an effort to reduce dog odors and dust in the home. Not only was the ozone unable to make much of a dent in this debris, it was potentially dangerous. Another of our clients destroyed their home by overdosing it on ozone using a commercial ozone generator which oxidized their carpet padding and other building components. Ozone for pet dander control is a bad idea.

At the end of the day, while we have verified that creating an anti-dust, hard surface, no-clutter environment, combined with regular cleaning and pet restrictions (no dogs in the bedroom), if there are animals in the home there will be animal dander throughout the home, moved there by the combination of shedding animals, moving air, and moving people.

At ALLERGENS in BUILDINGS, RECOGNIZING we discuss and provide photos of common indoor allergenic particles found in homes and in the work place.

At ALLERGEN TESTS for BUILDINGS we discuss testing buildings for the presence of animal allergens or other allergens such as insect fragments or fecals.

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Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

On 2017-05-07 - by (mod) -

Llaird

You can damp wipe and HEPA vacuum all surfaces in the apartment. That will reduce the level of dog or cat dander and other allergens. No amount of vacuuming (nor steam cleaning) will remove all of the possible allergens or dander deposits in wall to wall carpets. If you're highly allergic you may prefer living with as many hard surfaces as possible: sheet vinyl & wood flooring are easier to clean to a low-dust level.

Drapes and area rugs can be cleaned out of the building and then returned.

On 2017-05-07 - by (mod) -

Christy:

You can collect a simple tape sample of the dust to send to any forensic lab, for which I'll include some suggestions below.

At DUST SAMPLING PROCEDURE is an easy inexpensive means of collecting settled dust that you could have examined (by a suitable lab) to identify its dominant particles. That can help decide if there is an unusual level of fiberglass, insect fragments, mold, or other irritating particles in indoor air by using a non-quantitative approach that is in most regards far more reliable than a brief air-sample.

Environmental Test Lab referrals from Daniel Friedman​​
​​
For environmental or forensic investigative support and lab work, you can use any forensic lab provided you first check that their area of expertise matches your needs.

For strange particle analysis, building dust analysis, fiberglass particle screening, mold contaminant screening contact these expert forensic microscopists

Daniel Baxter (dbaxter@san.rr.com) or

Larry Wayne (lew@forensica.com)

For mold or general environmental dust samples also contact our backup

Susan Flappan
11020 W. 122nd St.
Overland Park KS 66213
913 322 2237. toll free number of 866 225 MOLD
http://moldetect.com/
sflappan@moldetect.com

EMS lab is a very large and competent network of labs offering a wide range of services
http://www.emlab.com

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On 2017-05-07 by llaird524@gmail.com

Just moved into apartment and the person before me had both cat and dog. Highly allergic and now always sick. What can I do?

On 2016-01-11 by Christy Doggett

We have built new house almost 11/2 years ago, and use hep filters in furnace (gas). We have a excessive amount of white looking dust that accumulate very quickly even after dusting and sweeping. We have two long hair cats but have had them for four years. My allergies are worst and again really notice more of this white like dust partial thru out the house. I have air cleaner but nothing helps. Can you direct me to a place where I can have this dust partial stuff analyzed ? I live in Lexington, ky. Thank you

Question: how to reduce an indoor dust mite problem

(Sept 7, 2011) Tansies said:
This article has been super helpful, I had no idea that humidity increased the incidence of dust mites! Its been quite rainy this past week and I can even feel that my couch, which is near the window is slightly moist to the touch, must be dust mite heaven! What is a good way to get rid of dust mites? for example in a couch where you cannot wash the cushions..?
Thank you

Reply:

Some suggestion for dust mite control

- Reduce humidity - search InspectApedia for "indoor humidity level targets" for the article
- Housekeeping - HEPA vacuum carpets and upholstered furniture
- Pets - high levels of animal dander, in my experience, can feed a booming dust mite population - back to housekeeping
- dust mite covers: for people who have dust mite allergies, you may want to use mattress and pillow covers that use special dust-mite resistant fabrics; I've found those work quite well

Don't expect nor seek to get rid of all dust mites. They're with us, sometimes I can even see them on people's eyelashes! Well, not without a microscope.

Dust sampling can tell you the overall dust mite level in an area or building.

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Continue reading at CAT DANDER in BUILDINGS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• ALLERGEN TESTS for BUILDINGS
• ALLERGENS in BUILDINGS, RECOGNIZING
• ANIMAL ALLERGENS / PET DANDER - home
• ANIMAL or URINE ODOR SOURCE DETECTION
• BLACK STAINS from ANIMALS
• CAT DANDER in BUILDINGS
• FIBER & HAIR IDENTIFICATION
• MOLD EXPOSURE STANDARDS
• OZONE MOLD / ODOR TREATMENT WARNINGS
• PET ALLERGENS / PET DANDER
• PET STAINS & MARKS in BUILDINGS
• URINE / ANIMAL ODORS IN BUILDINGS - home
• UV LIGHT BLACK LIGHT USES

Suggested citation for this web page

ANIMAL ALLERGENS / PET DANDER at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING ODOR DIAGNOSIS & CURE

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