Asthma Pets

According to the National Heart, Lung and Blood Institute, the number of asthma and allergy cases is on the rise: nearly twice as many cases are currently reported as compared to twenty years ago. What has caused this drastic increase?

Scientists are working frantically to figure out what can be done to reverse this trend. While no conclusive solution has emerged yet, some interesting theories are being tested. One of the leading theories, known as the hygiene hypothesis, examines the potential risks of “over-cleanliness” versus the potential benefits of allergen exposure at a young age. However, the hygiene hypothesis is still highly controversial.

The Hygiene Hypothesis

Modern, sterile living conditions result in less exposure to a variety of toxins and microorganisms at an early age. The hygiene hypothesis suggests that this reduced contact with potential allergens has ironically caused the surge in allergy and asthma cases.

Simply, the argument claims that a lack of exposure to these stimuli is detrimental to the developing immune system, placing individuals at a greater risk of overreacting when they are eventually exposed to allergic triggers later in life. Essentially, the hygiene hypothesis asserts that the immune system should be tested and trained at a young age in order to be properly balanced.

Mixed Results

Compelling scientific evidence supports the hygiene hypothesis. Several studies have been published providing support for the notion that kids who grow up in homes with cats and dogs have far fewer problems with allergies and asthma. The research argues that exposure to animal dander and the rich variety of allergens associated with pets stimulates the production of the immune system’s T-cells early on.

However, in the last couple of years there has been a backlash in the scientific community: recent reports claim that exposure to dogs and cats at a young age can actually increase the risk of developing asthma and allergies. Clearly, the validity of the hygiene hypothesis is still in question.

The Complicated Truth About Asthma

That can we make of all of this, and what is the consensus of the research results? Unfortunately, it remains unclear whether having pets at home bears any weight at all on preventing or promoting the development of asthma and allergies. What does remain clear, however, is that people who have already developed asthma or allergies should avoid potential triggers such as animal dander, pollen and tobacco smoke.

An Answer in Sight

Part of the difficulty in obtaining conclusive evidence in this debate is the complexity of designing a properly controlled study. Because cat and dog allergens are present everywhere, non-pet owners have often already been exposed.

A three and a half year research study, which began in 2001, was designed to reveal how exposure to cat, dog and mite allergens in developing children would affect their development of asthma and allergies later in life. This ongoing study, under the direction of members of the North West Lung Research Centre in Manchester, UK, differs from others in that it is performed longitudinally over a long period of time and is stringently controlled.

Two groups are under observation: an active group with strict instructions and hygienic guidelines intended to reduce the level of allergens in the home and a control group. Hopefully, the results of this study will provide a better idea of whether having pets at home influences our children’s health.