Pet owners and risk factors in cardiovascular disease

To the Editor: We refer to the recent article by Parslow and Jorm1 and the editorial by Headey2 on the link between pet ownership and health outcomes. There is no evidence that pet ownership per se confers cardiovascular benefits. Indeed, the findings of the study were that pet owners were more likely to smoke, had a higher diastolic blood pressure and a higher body mass index than the non-pet owners. The editorial points out that, based on sociological studies, it is likely that pet ownership does have a positive effect on health, but the medical data demonstrating how this is achieved are lacking.2

Might there be other negative effects of pet ownership on health outcomes?

A patient under our care recently demonstrated the potential risks involved in pet companionship for elderly people. An 81-year-old woman who was living independently was admitted after a fall caused by tripping over her delightful Himalayan Persian cat.

Her presenting symptom was severe back pain exacerbated by weight bearing. However, no bony abnormality was identified. She had difficulty mobilising initially, and the outcome of her fall was significant morbidity with some loss of her previous mobility, even on discharge. She stayed in hospital for 12 days. A follow-up phone call revealed that the patient was still experiencing difficulty mobilising some 2 weeks after discharge.

This case raises the possibility that the risks may outweigh the benefits of pet ownership in elderly people who are already at risk of falls. A MEDLINE search, using the terms elderly, trauma, cat, pet and fall (and combinations of these), did not reveal any relevant literature. A recent case report highlighted other cardiovascular issues relating to cat ownership.3 It described a patient who had recurrent episodes of syncope whenever her cat slept on the right side of her neck. The underlying mechanism was carotid sinus hypersensitivity. She required a single-lead ventricular pacemaker and for the cat to lie on her left side.

Anecdotal evidence from colleagues highlighted the danger of “dogs taking elderly patients for walks”, resulting in rotator cuff injuries. Additionally, older patients with peripheral vascular disease and fragile skin have presented with non-healing ulcers from dog scratches.

Pet ownership for the purpose of modifying cardiovascular risk factors would seem to be unwise in this population. However, the benefits of companionship and the pleasure derived from pets may outweigh the risk of falls for many elderly patients. Should we be doing more “cat scans” or “pet scans” in older patients?