Pet Allergy

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 a number of allergenic proteins in their urine, sweat and saliva. These body fluids adhere to the skin life for example when a cat cleans itself.

Cat dander is the most common inhaled allergen source after house dust mite 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). Indeed, they may persist for many months after an animal has left a house. The best way of avoiding pet dander is obviously do not have a pet. If you have a pet and are determined to keep it, then there are still various measures you can take to cut down on pet allergen exposure, from controlling the animal's access to certain rooms to using an effective air purifier to trap dander particles.

Pet allergies are known to play a role in:

• Asthma - around 40% of people with asthma are sensitive to cat allergen.
• Atopic dermatitis - characterised by a skin rash.
• Conjunctivitis - this is inflammation of the linings of the eyelids.
• Rhinitis - with runny nose and sneezing.

People with atopy, a tendency to allergy, should avoid owning pets if possible. Even if you are not allergic to the pet at present, continued exposure could eventually cause sensitisation, leading to allergic symptoms.

In an allergic person, exposure to certain proteins in animal dander will cause the immune system to over-react and cause an overproduction of Immunoglobulin E (IgE). The IgE attaches itself to mast cells, which are a type of immune cell, causing them to produce the chemical histamine. It is the histamine which causes allergic symptoms like swelling, redness, watery eyes, coughs and sneezing and also why the main drugs for allergy are called antihistamines.

Pet dander is very sticky and stays on people’s hair, clothes and other belongings for long periods of time, and thus travels to offices, kindergartens, planes etc.

What animals cause allergy problems?

These animals can all cause pet allergy:

• Cats
• Dogs
• Birds
• Mice
• Rats
• Guinea pigs
• Rabbits
• Hamsters

Male cats shed more allergen than females, and cats shed more allergen than dogs. Horses produce very powerful allergens and old mattresses stuffed with horsehair can produce symptoms. Snakes, lizards and other reptiles, and even insects may shed dander-like skin particles into the air. Fish are perhaps the only companion animals not associated with allergy.

Four main cat allergens have been identified and studied. The two main ones are Fel d1 and Fel d4 (Fel stands for Felis – the scientific name for a cat). Fel d1 is found in a cat's sweat and Fel d4 in its saliva. The minor allergens are Fel d2 and Fel d3 found elsewhere such as urine.

The two main dog allergens are Can f1 and Can f2 which are found in dog saliva. Can stands for Canis the scientific name for a dog.

The dog genome does not, as far as we know, vary so much between species that some have lower allergen levels than others. Therefore, all dog species produce the same amount of allergen in their secretions. Any differences probably relate to the length of the dog's coat and how much hair it sheds, or maybe how much it sweats. There are around 60 breeds of dog that are said to be hypoallergenic - generally, as you might expect, those which are hairless or have short coats and therefore do not shed as much. Examples include various breeds of terrier and former US President Obama's dog (Bo, The First Dog) who is a Portuguese water dog, because one of his daughters is allergic. A recent research study looked at the amount of allergen shed by different dog species and found that hypoallergenic dogs do not shed significantly less allergen than other breeds.

To learn more about dog allergies visit our Dog Allergy Information page.

All allergen avoidance / environmental allergen control is important. The following guidelines should help:

• Do not let your pet roam the house at will. Animals shed allergen-containing dander wherever it goes and it persists for months, both in the air and on the surfaces it sticks to.
• Never allow a pet to enter the bedroom of the allergic person. This should always be a low or no allergen zone. The worst thing you can do is to allow the animal onto the bed.
• If you can, confine your pet to outdoors or to 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 outdoors 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 a good 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 because this is when allergen starts to spread.
• Reduce dander spreading by washing your pet regularly with PET+ Pet Shampoo. This has been shown to reduce allergen load by more than 85%.
• Be sure to wash your hands after touching your pet. Cuddling your pet is part of the fun of ownership, and it is therapeutic for both of you. But always wash your hands thoroughly afterwards, for pet dander spreads so 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. The allergens can reach your eyes and nose and you will suffer for it.
• 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, your carpet with a wooden surface, and getting rid of any unnecessary soft furnishings.
• A HEPA air purifier like the IQAir HealthPro 250 or the Blueair 480i SmokeStop will capture and retain animal dander particles out of the air, and lower the allergen burden in bedrooms or other rooms.