Are pets and animals important for your health?

Posted on Sat, 12 Oct 13

In modern urban environments often the only interaction people have with the animal kingdom is with rats or pigeons. The divide we have created between us and other animals may have direct implications for our health.

Studies on the relationship between our health and regular interactions with wild animals such as enjoying birds in your garden, or spotting wildlife on a morning walk are few, if any, but there are some interesting lines of evidence that suggest a health effect. 

An unusual example comes from a study of bottlenose dolphin therapy for depression. A group of depressed patients either played or swam with dolphins for 1 hour a day, 5 days a week for 2 weeks. As you might expect, at the end of the study there was a significant reduction in depression in the treatment group compared to control group (who did incidentally get to play with the dolphins at the end of the study period as well, so as not to be too disappointed) (1).

But perhaps more relevant evidence of a beneficial interaction between animals and us comes from companion animals, especially dogs, which are estimated to have been domesticated some 15,000 years ago (2).

Dog and cat owners have been found to make fewer annual visits to their GP and are less likely to be on medication for heart problems and sleeping difficulties (3). In addition a remarkable study found that patients with heart disease who owned a dog had a greater than 600% reduction in risk of dying (4). A big part of the benefit of companion animals appears to be reductions in stress, anxiety and loneliness (5).

One possible explanation for these observations is that dogs increase social interaction, such as by attracting attention from passersby when out for a walk (6). Social interaction alone has potent health effects, but there is also evidence of a more direct effect. Just five minutes of interaction with a dog has been shown to produce measurable changes in stress hormones such as cortisol (7).

References:

1.  Antonioli C, Reveley MA. Randomised controlled trial of animal facilitated therapy with dolphins in the treatment of depression. BMJ. 2005 Nov 26;331(7527):1231.

2. Savolainen P, Zhang YP, Luo J, Lundeberg J, Leitner T. Genetic evidence for an East Asian origin of domestic dogs. Science. 2002 Nov 22;298(5598):1610-3.

3.  Headey B. Health benefits and health cost savings due to pets: preliminary estimates from an Australian national survey. Social Indicators Research. 1999; 47 (2): 233–243

4.  Friedmann E, Thomas SA. Pet ownership, social support, and one-year survival after acute myocardial infarction in the Cardiac Arrhythmia Suppression Trial (CAST). Am J Cardiol. 1995 Dec 15;76(17):1213-7

5.  Muñoz Lasa S, Ferriero G, Brigatti E, Valero R, Franchignoni F. Animal-assisted interventions in internal and rehabilitation medicine: a review of the recent literature. Panminerva Med. 2011 Jun;53(2):129-36.

6.  McNicholas J, Collis GM. Dogs as catalysts for social interactions: robustness of the effect. Br J Psychol. 2000 Feb;91 ( Pt 1):61-70.

7.  Barker SB, Knisely JS, McCain NL, Best AM. Measuring stress and immune response in healthcare professionals following interaction with at therapy dog: a pilot study. Psychol Rep 96:713–729, 2005.