Dander – Signs and symptoms, Treatment


Also called: Pet Dander, Cat Dander, Animal Dander, Dog Dander


Dander consists of small scales or flakes of dead skin cells that are continually shed by all animals. Light and sticky, dander is easily transported by air currents and often becomes attached to objects or people. In the household, dander is a common element of house dust, particularly in homes where cats or dogs are present.

The proteins in dander can trigger allergic reactions in sensitive people, causing symptoms such as sneezing, itchy and watery eyes, coughing, wheezing and difficulty breathing. In rare cases, an allergic reaction may progress to a severe and potentially deadly allergic reaction known as anaphylactic shock.

Dander can also trigger asthma attacks in people with allergic asthma, a condition in which the airways become blocked or narrowed causing shortness of breath or difficulty breathing because of an allergic reaction.

All furred and feathered animals shed dander, regardless of hair length or type. Because household pets are the animals most commonly in contact with people, their dander is more commonly associated with allergies. According to the American Academy of Allergy, Asthma and Immunology (AAAAI) nearly 10 million pet owners are allergic to their animals. 

About dander

The term “dander” refers to the small dead skin cells continually shed by animals. All furred and feathered animals shed dander, including cats, dogs, hamsters, guinea pigs, ferrets and birds. Dander itself is very light, sticky and easily airborne. Riding on air currents, dander can stay airborne for hours until it settles on a surface, where it can remain for months.

Because dander is so easily transported and tends to stick around, it can (and does) enter areas where animals do not reside. Researchers have documented comparatively high levels of dander in office buildings and homes that do not have pets.

Dander triggers an allergy when the flakes are inhaled into the respiratory system, come into contact with the eyes or get lodged inside the mucous membranes that line the nasal passages. Although the saliva, urine and blood of animals can also trigger allergic reactions in sensitive people, dander is the most common cause of animal allergies.

In contained areas, such as a home, the accumulation of dander is likely to trigger an allergic reaction in people with dander allergies. Animal dander is commonly found in household dust. By contacting clothes or other material outside, dander can be easily transferred into the house.

Although all furred and feathered animals that have skin produce dander, there are differences in the amount produced. For example, young animals tend to shed less and therefore produce less dander. The amount of dander can also depend on the size of the animal. A smaller animal will produce less dander than a larger one, for instance. Recent research has also suggested that the color of an animal’s fur may play a role in the severity of a patient’s symptoms. According to the study, exposure to dark cat hair resulted in a greater amount of symptoms. However, more research is needed.

Furthermore, some dogs shed their skin more quickly than others. Cocker spaniels, German shepherds and Irish setters shed their skin more frequently than poodles and schnauzers. Dog breeds that shed their skin less frequently generally produce less dander.

Dander is specific to particular animal species because the cells and proteins in dander vary. Dog dander is different than cat or bird dander, for example. As a result, people with allergies to dog dander may not be allergic to cat dander. However, some people have allergies to both dogs and cats, because they are allergic to the particular cells and proteins in both types of dander.  

Because all animals have skin, there is no such thing as a hypoallergenic animal. Sensitive people may have an allergic reaction to any animal regardless of hair length or type, size or breed. All of the following animals have dander that can potentially trigger an allergy (Note: This is not a complete list):


People with dander allergies can safely keep pets that do not have fur or feathers, such as snakes, turtles and fish.

Related allergies and conditions

Dander is the primary cause of animal allergies. Dogs and cats are the primary sources of animal allergies because they are the animals most commonly kept inside the home. However, other furred or feathered animals (e.g., ferrets, hamsters, guinea pigs, monkeys, horses, rabbits and birds) also cause dander allergies.

Dander allergies are related to a number of other conditions. People with pollen or dust mite allergies may be more likely to also have dander allergies. Animal dander breaks into tiny particles that frequently become a component of household dust. Also, people with outdoor allergies might experience reactions after contact with an animal, even if they do not have an allergy to the animal. This is because outdoor allergens such as pollen can get caught in the animal’s fur or feathers. 

Allergies to dander may take many forms, including:

  • Allergic rhinitis.  An inflammation of the mucous membranes that line the nose, causing nasal congestion, sniffling and sneezing. Dander that is inhaled into the nasal passage can trigger this condition.
  • Allergic conjunctivitis. An inflammation of the tissue lining the inside of the eyelid that produces irritation and tearing of the eyes. Animal dander that comes into contact with the eyelid can trigger this response.
  • Contact dermatitis. An inflammation of the skin that is caused by direct contact with an allergen. It usually appears as a red, bumpy skin rash. Animal dander coming into contact with the skin can trigger this type of reaction.
  • Asthma. A condition in which the airways become blocked or narrowed causing coughing, shortness of breath and breathing difficulty. Asthma can be allergic and non–allergic in origin. Dander allergens can cause both acute and chronic asthma symptoms. The incidence of asthma–like symptoms in owners of furred and feathered animals is significantly higher than those who are exposed to other animals. There is also evidence to suggest that people with dander allergies are at increased risk of developing chronic asthma.

Signs and symptoms

Allergic reactions caused by dander generate a variety of symptoms, including:

  • Itchy eyes and nose
  • Nasal congestion
  • Headache
  • Fatigue
  • Hives
  • Coughing
  • Wheezing
  • Shortness of breath

The severity of allergic reactions to dander varies between patients. In rare cases, an allergic reaction may progress to a severe and potentially deadly allergic reaction known as anaphylactic shock. This requires a visit to the emergency room, especially in the case of severe breathing difficulty.

Diagnosis methods

Diagnosis of a dander allergy requires a physician to take a complete medical history, including a list of symptoms. A physical examination will also be performed.

If the physician suspects an allergy, a skin test or blood test will be performed. During skin testing, a physician will prick or inject an extract of an allergen into a patient’s skin and wait 10 to 20 minutes to see if there is a reaction. The development of a small, raised, reddish area generally indicates a positive reaction.

Skin testing is not practical for those with certain skin conditions. In such cases, a blood test such as a radioallergosorbent test (RAST) may be used to pinpoint the allergen causing a reaction. In this process, a patient’s blood is checked for an increase of the IgE antibody to a particular allergen, which indicates a potential allergy.

Treatment and prevention

For people with dander allergies, the only way to prevent an allergic reaction is to avoid contact with problem types of dander as much as possible. People with dander allergies should particularly avoid having an animal in their house. Dander is small and sticky and can stay airborne for extended periods of time. Dander allergens can adhere to walls, furniture, clothing, carpet, air ducts and numerous other places indoors. As people spend much of their time at home, avoiding exposure to dander allergens in the home is vital for allergic individuals.

The best method for avoiding dander in the home is the removal of pets from the home. Other methods, such as cleaning the home, only remove the allergen partially and temporarily.

Removal of a pet is often effective enough that the patient does not require any additional treatment. However, patients should be aware that it may take six months or longer to completely rid a home of dander after a pet is removed. Thorough cleaning, such as scrubbing the walls and replacing furniture and carpeting, can speed up the process.  

Physicians may recommend removal of a pet because continued exposure could lead to other health problems, such as asthma. It can also worsen the severity of the patient’s reactions. However, most people are unwilling or unable to part with their pets. For people with allergies to dander who decide to keep their pet in the home, the following steps can help reduce their allergen exposure:

  • Keep animals out of the bedroom at all times and designate “animal–free” areas of the home, if possible. Keeping an animal outside is often only a temporary solution, because the pet’s dander will eventually build up within the house.

  • Run portable air purifiers throughout the home and consider using a HEPA filter.

  • Clean, dust and vacuum regularly, using a vacuum cleaner with a HEPA filter.

  • Frequently change furnace and air filters.

  • Do not permit any animals on furniture.

  • Consider placing plastic covers on upholstered furniture or purchase vinyl or leather furniture.

  • Remove carpeting and rugs in the home and replace them with tile or hardwood flooring.

  • Wash hands after handling animals.

  • Have the animal bathed by a nonallergic individual once or twice a week.

  • Have a nonallergic individual brush the animal daily outdoors.

  • Have the animal’s litter box, cage and bedding cleaned by a nonallergic individual.

  • Use a covering for the mouth and nose (e.g., surgical mask) when cleaning inside, or let someone else handle any indoor cleaning.

  • Use allergen-resistant bedding.

  • Wash bedding in hot water.

  • Wash clothing frequently. Certain types of clothing may also be more prone to collecting dander. Research has found, for instance, that wool sweaters collected up to 10 times more dander than other types of clothing.

  • Provide a well–balanced diet for pets. A healthy animal may lose less fur and feathers, thereby reducing levels of indoor dander.

  • Avoid hugging and kissing animals.

  • Avoid visiting the homes of people with pets.

Dander allergies can also be treated with medication. Over-the-counter antihistamines can relieve itchy eyes. Nasal decongestants can reduce congestion. In people with allergic asthma, asthma medications may be required to help prevent asthma attacks.

Allergy immunotherapy is also able to successfully prevent or reduce allergy symptoms in some patients who are allergic to dander. Immunotherapy, also known as allergy shots, involves a patient receiving regular shots of a low dose of an allergen over a period of months or years. Over time, the patient is able to build up a resistance to the allergen, and can tolerate normal exposure to the allergen without an allergic reaction.

Questions for your doctor regarding dander

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to dander:

  1. Do my symptoms indicate that I am allergic to dander?
  2. What methods will you use to determine if I am allergic to dander?
  3. Does this condition pose a danger to my overall health?
  4. What are my treatment options?
  5. Am I a candidate for allergy shots?
  6. Are there any types of cats or dogs that are “allergen free” and won’t cause me to have a reaction? Are certain breeds better than others?
  7. Can I still have a pet if I am allergic to dander?
  8. Are there any medications that will allow me to be around animals for a short period of time?
  9. If I don’t own a pet, can I still have a reaction to dander in my home?
  10. What steps can I take to reduce the level of dander in my home?
  11. Would I benefit from using a HEPA filter or a vacuum with a HEPA filter?
  12. Is my child more likely to develop dander allergies because I have the condition?
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