3. Allergen exposure/allergen-specific immunotherapy. 3.1. Pets.

Level of recommendation	Statement
A/B	Background: Several epidemiologic studies have shown that keeping dogs in the first years or the first 3 years of life has a primary protective effect against the development of allergies and asthma. There is still conflicting data with regard to keeping cats or other typical pets.
	Recommendations: For families without a recognizably increased risk of allergies, keeping of cats or dogs should not be limited for reasons of primary allergy prevention. (A)
	Families with an increased risk of allergies or with children with pre-existing atopic eczema should not start keeping a cat. (B)
	Families with an increased risk of allergies should not be advised against keeping dogs. (B)
	Statement: With regard to pets other than cats and dogs, no recommendations can be made on the primary prevention of allergies and asthma. There is no evidence for giving away existing pets for reasons of allergy prevention.
Level of evidence	Dogs: Marrs 2019 (1–); Collin 2015 (2+); Fall 2015 (2+); Hesselmar 2018 (2–); Al-Tamprouri 2019 (2++)
	Cats: Al-Tamprouri 2019 (2++); Milanzi 2019 (2++)
Level of consensus:	Strong consensus