Animal dander (particularly cats) has been blamed for a great number of allergies and asthma. However, recent research has shown that pet ownership may actually be one of the best ways to guard against initially developing those adverse reactions.

Some highly-publicised research in recent years has suggested that having pets around young children may actually protect them from allergies. A study published in 2011 in Clinical & Experimental Allergy showed that infants living in homes with cats have 50 per cent fewer cat allergies than children not exposed to kitties from birth to one year of age.

“The old thinking was that, if your family had a pet, the children were more likely to become allergic to the pet. And if you came from an allergy-prone family, pets should be avoided,” says researcher James Gern, a paediatrician at the University of Wisconsin-Madison, in the Journal of Allergy and Clinical Immunology.

Prolonged cat ownership and early life exposure to cats may have a protective effect against early asthma indicators

However, a growing number of studies have suggested that kids growing up in a home with “furred animals” – whether it’s a pet cat or dog or exposed to large farm animals – will have less risk of allergies and asthma.

Gern explained that children who grow up with a pet are at lowered risk of asthma and allergies. According to his research, infants with a cat in the home had a 14 per cent smaller chance of displaying pet allergies.

Essentially, immediate exposure to a pet boosts an infant’s or child’s immune system, providing a health benefit you might not expect.

Most importantly, before you think about finding a pet a new home, you need to figure out if you – or your children – are in fact allergic. Though it seems as if pet allergies should be obvious, your pet may not be causing your symptoms. Asthma can be triggered by substances other than pet dander, such as dust mites, exhaust, smoke, pollen and cold air, or even allergens from rodents and cockroaches. For some (but certainly not all) asthmatics, pets may actually be a relatively minor contribution to their symptoms and some asthmatics may not be allergic to pets at all.

New research makes it clear that, while a large number of asthma cases in the US are associated with allergies, many others – roughly 45 per cent – are not.

“This study tells us that allergy can be a major factor in asthma,” Peter Gergen, of the US National Institute of Allergy and Infectious Diseases, said. “But this study also tells us that there are many people who get asthma who don’t have allergies.”

“There’s no reason to consider removing a pet unless you can demonstrate that there is a sensitisation to that type of animal,” says Gregory Diette, an asthma specialist and associate professor of medicine at the Johns Hopkins University School of Medicine, in Baltimore, Maryland.

Furthermore, if asthma is well controlled with appropriate medication, airways can be desensitised to overreacting to triggers such as cats.

In the last dozen years, numerous studies have emerged that suggest children who grow up with a dog or cat are less likely to develop allergies, asthma and respiratory and ear infections than those without pets.

The journal Pediatrics showed that infants who had contact with cats in the home had 31 per cent fewer respiratory tract illnesses and infections, 44 per cent fewer ear infections and 29 per cent fewer antibiotic prescriptions than children with no contact with cats.

A 2009 study in The Journal of Allergy and Clinical Immunology showed that children who lived with both a cat and a dog were less likely than other children to have allergies at age 13. A year before, Clinical & Experimental Allergy carried a study which concluded that exposure to cats in infancy, especially around the time of birth, is associated with changes in immune development and a reduction in wheezing and allergic hypersensitivity.

Research conducted in 2002 and reported by the Journal of the American Medical Association showed that infants exposed to two or more dogs or cats during their first year had fewer allergies not only to pets but also to dust mites and pollen, which are major causes of asthma.

This findings suggests that prolonged cat ownership and early life exposure to cats may have a protective effect against early asthma indicators, such as wheeze, as children reach age five.

If a cat lived in the home, infants were less likely to show evidence of pet allergies – 19 per cent vs 33 per cent.

They also were less likely to have eczema, a common allergy skin condition that causes red patches and itching.

In addition, they had higher levels of some immune system chemicals, a sign of stronger immune system activation.

Christine Buckley is a senior respiratory physiotherapy clinician