Research investigates how pet allergens can protect children from sensitisation to allergens.

Dog and cat allergies affect between 10-20% of the world’s population, with children being especially susceptible. However, new research has revived an old debate, do pets make children who are prone to allergies more or less likely to develop asthma and allergies? A recent study conducted in Finland found that early exposure to pets, particularly dogs, conferred protective benefits against sensitisation towards animal allergens and asthma in children.

Childhood allergies are an increasingly common health issue worldwide, impacting millions of children each year. Symptoms vary widely, from mild rashes and sneezing to severe respiratory distress and anaphylaxis. The reason for this rise is multifactorial, with contributions from genetic predispositions to environmental factors. The hygiene hypothesis, for example, suggests that reduced exposure to pathogens early in life may hinder immune system development, making children more susceptible to allergies.

New study on childhood allergies

The study included 203 children, aged 4-17, with asthma and 33 controls. The study explored allergic responses to specific proteins in animal fur, such as IgE sensitisation to dog, cat, and horse allergens and assessed lung function. They also collected data on household pets through parent-reported questionnaires.

The results revealed a significant correlation between sensitisation to certain furry animal allergens, such as lipocalins, and markers of type 2 inflammation, including blood eosinophilia and fractional exhaled nitric oxide (FeNO). This correlation suggests that sensitivities to specific allergens are closely linked to asthma and inflammation in children.

Pets as protective factors

However, children who lived with a dog actually reported fewer asthma symptoms, had lower levels of IgE sensitisation, and displayed less blood eosinophilia than those without. This points towards a possible protective effect of dog ownership against the development of allergies and asthma, offering a new perspective on the role pets play in shaping immune responses from an early age.

The study also found no direct connection between sensitisation to furry animal allergens and abnormal lung function, challenging previous beliefs that these allergens could worsen pulmonary outcomes. Moreover, the methacholine challenge, used to identify airway hyper-responsiveness, did not show any significant links with furry animal allergens, underscoring the complex relationship between sensitisation and lung health.

Research impact

This study adds to the growing evidence that pets may play a dual role in child health. While certain allergens from pets can indeed trigger inflammation, the consistent, early exposure may simultaneously train the immune system: hormesis. However, while researchers propose that pet ownership could be a protective factor, they caution that this benefit is likely limited to certain individuals and may not apply universally.

With childhood asthma rates still climbing globally, this research could offer practical insights for parents and healthcare providers. For now, it seems plausible that, under the right circumstances, welcoming a dog into the home could bring health benefits along with companionship. While future studies may provide further insights, today’s findings underscore the nuanced relationship between pets and paediatric asthma, suggesting that perhaps not all pet allergens are created equal when it comes to immune system training.

Key study findings:

• Children with dogs have fewer asthma symptoms, lower IgE sensitisation, and less blood eosinophilia
• Protective effect of dog ownership against the development of allergies and asthma
• No connection between sensitisation to animal allergens and abnormal lung function