Research suggests preschoolers with pets have fewer food allergies. 

Children exposed to indoor cats and dogs during foetal development and early infancy have fewer food allergies, according to a massive study of more than 66,000 children up to the age of three in Japan.

Across some high-income countries, more than one in ten children are diagnosed with food allergies, and the incidence of food allergies in children continues to rise. Previous research has suggested a potential link between dog or farm animal exposure in pregnancy and early childhood and the reduction of food allergies.

In the latest study, researchers found that 22 per cent of the children had been exposed to pets during the foetal period, and that those exposed to indoor dogs were significantly less likely to experience egg, milk, and nut allergies, while children exposed to cats were significantly less likely to have egg, wheat, and soybean allergies. 

Surprisingly, children exposed to hamsters (0.9 percent of the total group studied) had significantly greater incidence of nut allergies.

The study is accessible here.