Cat and dog exposure and respiratory morbidities in cystic fibrosis

Objective To understand the triggers that may impact respiratory health in cystic fibrosis (CF), including the effects of pets, because environmental factors contribute to one-half of the variation in lung function in patients with CF.

Study design A total of 703 subjects with CF were recruited through the US CF Twin-Sibling Study. Questionnaires were used to determine the presence/absence of cats and dogs in households with a child with CF. Questionnaires, chart review, and US CF Foundation Patient Registry data were used to track respiratory and infection outcomes.

Results Within the sample, 47% of subjects reported owning a dog, and 28% reported owning a cat. After adjustment for demographic factors, dog ownership was not associated with any adverse clinical outcomes, and cat ownership was associated an increased risk in developing nasal polyps (aOR 1.66; P =.024) compared with noncat owners. Subjects who owned both cats and dogs were twice as likely to report wheezing compared with other subjects (aOR: 2.01; P =.009). There were no differences in prevalence and age of acquisition for the common CF respiratory pathogens Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus between cat/dog owners and noncat/dog owners.

Conclusions Cat ownership was associated with a greater frequency of developing nasal polyps and combined cat-dog ownership was associated with a greater rate of wheezing. Prospective studies are needed to confirm these associations and the potential psychosocial benefits of cat and/or dog ownership.