Pet allergies are very common, especially in people who have other allergies or asthma. Most pet allergies are associated with cats, dogs, rodents and horses however people can also have allergies to animals with feathers.
Pets produce dander. Pet dander is the name given to microscopic skin flakes shed by animals. It is a bit like dandruff flakes only smaller at around 2-3 microns in size. Animals shed several allergenic proteins in their urine, sweat and saliva. These body fluids adhere to the skin for example when a cat cleans itself. The protein can cause severe allergic reactions for some people. Pet dander can easily become airborne and inhaled. Unfortunately, it is also very sticky and can cause allergic reactions for extended periods of time (up to 20 weeks).
Cat dander is the most common inhaled allergen source after house dust mites and pollen. Other animals commonly kept as pets, such as dogs, mice and guinea pigs may also cause allergic reactions. Pet allergens are widely distributed in the air because they are so light, and they remain airborne for several hours before settling only to be easily stirred up again.
Allergens from cats and dogs are found in skin cells the animals shed as well as in their saliva, urine and sweat and on their fur. Pet saliva can stick to carpets, bedding, furniture and clothing. Dried saliva can become airborne.
Allergens from rodent pets such as mice, gerbils, hamsters and guinea pigs are usually present in dander, hair, saliva and urine. Dust from litter or sawdust in the bottom of cages may contribute to airborne allergens from rodents.
Rabbit allergens are present in dander, hair and saliva.
Those with an allergy to pets will find that their immune system overreacts to certain animal proteins, including those from the hair, saliva or urine. This in turn produces hay fever like symptoms (histamine) as the lining of the nasal passages become inflamed (allergic rhinitis). It is the histamine which causes allergic symptoms like swelling, redness, sneezing, runny nose, itchy red or watery eyes and possibly a cough. Some people may also experience skin inflammation (allergic dermatitis). Therefore, the main treatment for allergies are called anti-histamine.
If your pet allergy contributes to your asthma, you may also have trouble breathing, chest tightness or pain, an audible whistling or wheezing sound when exhaling, trouble sleeping caused by shortness of breath, coughing or wheezing.
Those with a pet allergy should ensure that any animal that lives in the house is kept clean and groomed. The following guidelines should help with avoiding pet dander:
- Do not let your pet roam the house at will. Animals shed allergens containing dander wherever they go, and it persists for months, both in the air and on the surfaces it sticks to.
- Never allow a pet to enter the room of the allergic person, this should always be a low or no allergen zone. The worst thing you can do is allow the animal onto the bed.
- If you can, confine your pet to outdoors or just one (well ventilated) room in the house, this gives the person who suffers with the allergy the best chance of controlling their symptoms. An outdoor pet should always be provided with a warm and comfortable shelter. If the pet is to be allowed controlled access to the house, the kitchen, with its lack of soft furnishings, is an appropriate choice but take care not to let your pet come into contact with food.
- If you can, you should put a cat outdoors as soon as it starts washing itself because this is when allergen starts to spread.
- Reduce pet dander by washing your pet regularly with pet shampoo. This has been shown to reduce allergen load by more than 85%.
- Be sure to wash your hands after touching your pet as pet dander spreads quickly and will be transferred from your hands to surfaces and the surrounding air.
- Try to avoid touching your face after handling a pet if you are allergic.
- Your carpets, curtains and soft furnishings will be infected with pet dander wherever your pet has been. Be sure to vacuum regularly with a vacuum that contains a HEPA filter and is leakage free.
- Daily damp dusting is also helpful.
- Do some home improvements, consider replacing your chairs with wooden or plastic ones, replace your carpet with a wooden surface and getting rid of any unnecessary soft furnishings.
- A HEPA air purifier will capture and retain animal dander particles out of the air and lower the allergen burden in other rooms.
Treating Pet Allergies
Dog and cat allergies can be treated with standard allergy drugs. Your doctor might recommend anti-histamines, decongestants or nasal steroids. Allergy shots are another option for people with dog allergies. They don’t work for everyone and a full course of treatment can take years, but they can really help some people.
Pet allergy is rarely caused by animals that don’t have fur, such as fish and reptiles, so these may be a more appropriate choice if you know you or a member of your family has an allergy to furry pets.
Sources used in writing this article are available on request
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Information written by the talkhealth team
Last revised: 18 March 2018
Next review: 18 March 2021