A. Experts used to think that being around pets at a young age did put children at risk of developing allergies and asthma. Doctors routinely recommended that parents, especially if they had a family history of allergies and asthma, get rid of pets, especially furry animals, before a new baby arrived.
A recent study in the Journal of the American Medical Association put that risk in doubt. The study, Exposure to dogs and cats in the first year of life and risk of allergic sensitization at 6 to 7 years of age1, concluded that having two or more dogs or cats around during the first year of life actually decreased a child's chances of developing allergies.
In this study, 474 full term babies were followed until they were 6-7 years old, at which time they underwent skin testing to see if they were allergic to common things, such as dust mites, dogs, cats, ragweed, and blue grass. Surprisingly, 33% of children with no exposure to animals and 34% of children with only one dog or cat tested positive on their allergy skin tests, but only 15% of the children with 2 or more dogs or cats had allergies.
So children with 2 or more dogs or cats had a little more than 50% less chance of developing allergies later in life.
Another study concluded that 'childhood exposure to cats was associated with a significant decrease in sensitization to cats in adulthood, particularly among those with a positive family history of atopy2.' A 'decrease in sensitization' means that less of these people were allergic to cats when they grew up.
Many other studies have shown a decrease in allergies and asthma among children who grew up on a farm and were around a lot of animals3.
References:1Ownby DR. Exposure to dogs and cats in the first year of life and risk of allergic sensitization at 6 to 7 years of age. JAMA - 28-Aug-2002; 288(8): 963-72
2Roost HP. Role of current and childhood exposure to cat and atopic sensitization. Journal of Allergy and Clinical Immunology - 01-Nov-1999; 104(5): 941-7
3Downs SH. Having lived on a farm and protection against allergic diseases in Australia. Clin Exp Allergy - 01-Apr-2001; 31(4): 570-5