Allergens Related To Pets

After dust mites, the second important allergy reason in houses is pets. Although many animals such as cat, dog, rabbit, bird, squirrel, and monkey might cause allergy, the most important one is cat.

Everybody deems that hair and feathers of pets make allergy. But this thought is wrong; hair itself is not allergen. Even if hair was allergen, it must be smaller than 5 micron in order to enter in bronchus and alveoli. The reason of the allergy related to pets is some materials that exist in various mucus (saliva, sebaceous gland, urine etc.). These materials stick on pet’s hair. Then this mucus dries up on hair and mixes in air in the form of small fragments. So the opinion of ‘long hairy animals cause more allergies’ is not right, but the longer the hair the more allergens it keeps. Most of the allergens related to mammals belong to lipocaline protein family; aerodynamic characteristics of these allergens are very similar too. Sometimes allergy might be caused not directly by animal, but by the aspergillus that has reproduced in animal’s food or water dish. 


The first cat allergy known in literature belongs to the year 1950: the person who became annoyed, sweated and had skin eruption when he entered the room where there was a cat was the first cat allergy patient in history. The animal the most frequently fed in houses is cat, because to look after a cat is easier and cats easily adopt house life. Allergens related to cats arise from secretory gland in the animal’s skin and from the animal’s saliva. While cat licks, its saliva sticks on its hair, the saliva dries up on hair and then mixes in air in the form of dust particles. Since the diameter of these allergens is a few microns, they can stay suspended on air for a long time and they can easily reach to lungs. The most important allergen on cat hair is Fel d 1. About %60 of these allergens are smaller than 2.5 micron and can stay suspended in air for a very long time. The sources of Fel d 1 allergen are sebaceous gland of cat under its skin, epitel cells on its skin and mucus on its posterior. Production of these is under the control of testosterone hormone. Researches shown that the allergen amount on castrated male cat’s skin 3-5 times decreased. Since cat and dog cubs’ skin is soft it less erupts, so the allergen amount it throws is less. As the animal gets older, its skin gets harder, so the allergen amount increases. Another characteristic of cat allergens is that they are very sticky. They stick on walls, carpets, furniture and dresses. Cat allergens might be exist in houses without cats, in hospitals and even in allergy clinics; this means that allergens are carried by dresses of people who have cats. 

The best thing to do for allergic people is to take the animal away from house. However, taking the animal away from house does not solve the problem. The allergens related to cats must be cleaned properly. According to researches, months and even years after cat is taken away, allergens still exist in house. One research proved that there found allergens at harmful levels for sensitive people in the house even five years after the cat was taken away.


Dogs cause allergies less than cats. Because dogs stay out of houses and be washed more than cats. Allergens related to dogs arise from the animal’s skin and saliva. It’s not true that some dog species cause fewer allergies.  


Although allergens related to horses cause symptoms on nose and eye, some allergic reactions such as asthma crisis might develop. Sources of horse allergens are horse’s mane, sweat and urine. These are very sticky like cat allergens and can be easily carried by dresses of people who are in contact with horses.There are children who pass through an asthma crisis after they were exposed allergens thrown from dresses of his brother who had ridden a horse. People who have horse allergy might have allergy to similar animals such as donkey, hinny and zebra. In addition, these people might have crosswise allergies to cat, dog and cavy. 


Cockroaches are the unwanted guests of houses. They are an important source of indoor allergens. Main domestic cockroach species are: Blatella germanica and Blatella americana. There are structural similarities between some allergens related to cockroaches (tropomyosin) and allergens related to mites. These creatures frequently live in kitchens, damp and dark places. Allergens exist in cockroach’s body parts, excrement, saliva and other mucus. %50 of people who have allergy to mites have allergy to antigens related to cockroaches. Cockroach allergy is more frequently seen on people who live in squatters and from low socioeconomic level. It is proved that cockroaches might cause allergic catarrh and asthma.


Mouse allergens are professional encountered allergens and cause asthma on people who work in laboratories. A recent research made in the USA showed that there are mouse allergens in %90 of researched houses at least in one room even if they are at low levels. The highest allergen amount was found in kitchens and in the rooms with high cockroach infestation. At %18 of examined children, skin test with mouse allergens was found positive. Positive level was found higher on children who show positive reaction and in houses with high allergen level.