Domestic cats may well be the culprits when it comes to provoking allergic reactions in people.
Scientists in Britain say cats are responsible for far more allergies than they have been credited with and suggest that keeping a cat can trigger allergic reactions in more than a quarter of the population.
The scientists from Imperial College, London conducted a study and have discovered that cats can cause breathing difficulties in people with some of the most common allergies.
The study looked for greater bronchial responsiveness, breathing problems similar to an early stage of asthma, as opposed to a full blown allergic reaction which can include runny eyes and skin rashes.
The team took dust samples from the mattresses of 1,884 European volunteers who were picked to be representative of the general population with regard to common allergies, which included dust mites, grass allergen and mould.
One in four of the volunteers had at least one allergy and the higher the level of cat allergens, the worse the lung function, even among those not allergic to cats.
They found in fact that those exposed to cat allergen had a greater respiratory sensitivity and were more likely to cough and wheeze.
Blood tests were also carried out to detect an antibody called IgE which is an indication of an allergic response.
Lead author Dr. Susan Chinn says the finding was unexpected and suggests that all allergenic individuals have signs of asthmatic responses if exposed to cat allergen, even when blood tests show they are not allergic to cats.
The researchers say the presence of increased symptoms suggests that a reduced exposure to cats may be benefit those with allergies, regardless of what their specific allergy is.
Dr. Chinn says people who are considering getting a pet need to be aware that cats are a problem for more people than was first realised.
The report is published in the current issue of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.