Environmental factors are responsible for the rise of atopic dermatitis in dogs: veterinarians should focus on modifiable influences

Over the past few decades, living conditions for people and dogs have changed significantly, along with a rise in allergy rates in both species. Since dogs share living spaces with humans and are subject to modern urban living, dogs now face increased exposure to pollution and less contact with farm animals and rural environments. Rural living promotes exposure to a diverse microbiota, which shapes the immune response. Pollution has many detrimental effects, ranging from epithelial damage to epigenetic changes. Pollutants disrupt epithelia, promoting low-grade chronic inflammation, dysbiosis, increased allergen penetration, and sensitization. Dogs today face higher exposure to air pollutants, chemicals, plastics, and surfactants, whether from detergents, topical products, or additives in commercial foods. While in the past dogs were fed a variety of home-cooked diets, table scraps, and raw meats, they are now more likely to be fed commercial diets regularly. Dogs today lead more sedentary lives, with increased obesity and reduced exercise, factors that are known to raise the risk of developing atopic dermatitis in humans. Many owners experience higher stress levels, and dogs tend to mirror their owners' stress and anxiety. The effects of environmental and dietary factors on canine atopic dermatitis are discussed, emphasizing the current evidence from published epidemiological studies. While some studies report associations, others identify early-life factors that can influence disease development. The companion Currents in One Health article by Marsella, AJVR, January 2026, addresses the theories proposed to explain these associations and provides pathogenetic mechanisms for the rise of allergic diseases in people and dogs.