There have been a number of studies in recent years that suggest that children who grow up in a home with a pet dog or cat can be less likely to develop allergies and respiratory conditions such as asthma. These studies first started to appear in 2006 and since then almost every one of them has shown a direct link between children having pets and not developing allergies, respiratory infections and ear infections.
Reasons why are unclear
However, while these studies have shown that this link exists, there has been no definitive proof offered about why this is the case. The most popular theory is that living with an animal exposes children to pathogens that they might not otherwise come across because of how sterile home environments are now becoming. These pathogens do not harm children but instead help build up their immune systems so that they are less likely to develop infections and other illnesses.
A study recently conducted by the University of Michigan has suggested that it may be the dog dust that is found in homes with pet dogs that is helping to protect children from certain illnesses. A study was carried out with three groups of mice, one group of which was exposed to dust from homes that had a dog living in them. It was found that this group of mice has less inflammation of the airways than the other two groups when they were all exposed to an allergen that is associated with asthma.
Further research indicated that it was a microbe within this dog dust that helped protect these mice against the allergens. The bacteria in question are named Lactobacillus johnsonii and researchers found a large supply of this microbe in the guts of the mice that were exposed to the dust from homes with a dog. It was found that the presence of this microbe reshaped the GI tract in terms of the organisms that were living there, and it was this change that led to the airways becoming less inflamed than the other groups of mice.
Exposure to certain pathogens can help health
Further research is needed to prove that this microbe is the same reason why children who live in homes where there are pets are protected against certain illnesses and infections as the mice. But, this study does seem to back up the existing theory about children needing to be exposed to some pathogens in order for their immune systems to develop and keep them protected.
One of the main reasons why people with young children are put off about having a pet in the home is because of the risk of allergies. However, most research shows that rather than causing allergies, pets can actually help to protect against them, and also reduce the chance of them developing other respiratory conditions such as asthma.