A number of studies in the past decade found that exposure to furry pets (e.g., cats, dogs) in the first year of a child's life is important for preventing later allergies (animal, food, pollen). A recent large study from Japan found that exposure to pet cats and dogs during pregnancy (developing fetus) and the first year of life confirms that furry pet exposure is important in reducing the risk of food allergies until at least 3 years of age.
While pet dogs kept inside had a protective effect, pet dogs kept outside did not. Also, the type of pet was important. Indoor pet dog exposure reduced the number of children with egg, milk, and nut allergies, while cat exposure was associated with fewer egg, wheat, and soybean allergies. However, these beneficial results did not apply to pet hamsters, birds, and turtles.
Why is this happening? It's thought that early in life exposure to furry pets (dander, microbes) helps train the developing immune system. Their gut microbes also have differences. By the way, other studies found that exposing a child in the first year of life to potential problem foods (e.g., peanut butter, eggs) reduces the incidence of that specific food allergy.
From Science Daily: Living with pet cats or dogs is associated with fewer food allergies in young children, study finds
In an analysis of over 65,000 infants from Japan, children exposed to pet cats or indoor dogs during fetal development or early infancy tended to have fewer food allergies compared to other children, according to a study published March 29, 2023 in the open-access journal PLOS ONE by Hisao Okabe from the Fukushima Regional Center for the Japan Environment and Children's Study, Japan, and colleagues. ...continue reading "Reduce the Risk of Food Allergies By Having Pet Dogs or Cats"