Allergies and autoimmune diseases (like diabetes type I) often run in families. These pathologies have both a genetic component and an environmental one. Studies show that early exposure to allergenic food or animals can reduce the risk of developing allergies in adult life.

Moreno and collaborators evaluated dog exposure among children for several years. They found that there was no association between early exposure to dogs and the developing type I diabetes.

The most accredited idea regarding the fact that early exposure to pets does not increase the risk of allergy, is the so-called “hygiene hypothesis”. The idea is that our need to have everything clean, reduces the possibility for children to have contact with bacteria and germs. Children’s immune system is, therefore, not trained in recognizing harmless agents from the pathological ones.

Several studies have found that exposure to animals during childhood, may indeed contribute to a lower risk of developing allergies.

Chen and collaborators, for example, studied more than 2,000 children with and without dogs during their first 6 years of age. They discover that the constant presence of a dog in children’s houses is correlated with a lower risk of developing pollen allergies.

A more recent study by O’Connor demonstrated that children exposed to pet allergens during infancy have a lower risk of developing asthma by 7 years of age. Researchers followed 560 children with a high risk of developing asthma from birth till 7 years. 29% of children actually developed the pathology. Higher concentrations of cockroach, mouse, cat and dog allergens at the age of 3 months were associated with lower risk of developing asthma.

Last year, Hesselmar published a paper demonstrating that allergies in children aged 7–9 years are reduced by having cats and dogs. Moreover, they assessed that the more pets, the lower the risk of developing allergies, suggesting a “mini-farm” effect.

To conclude, don’t be afraid of keeping your pets near your newborns.

And, most importantly, don’t worry if you don’t manage to keep your house clean. Dust and bacteria will prevent the development of asthma and allergy in your children 😉

References:

Chen et al., “Dog ownership and contact during childhood and later allergy development”, (2008), doi:10.1183/09031936.00092807

Hesselmar et al., “Pet-keeping in early life reduces the risk of allergy in a dose-dependent fashion”, (2018), https://doi.org/10.1371/journal.pone.0208472

Moreno, “Early animal exposure and childhood illness”, (2017), doi:10.1001/jamapediatrics.2016.3121

O’Connor et al., “Early-life home environment and risk of asthma among inner-city children”, (2017), 10.1016/j.jaci.2017.06.040