Cancer and Animals

How our pets can help us

Posted Apr 16, 2018

Dana Jennings, who wrote a blog about his experience with advanced prostate cancer for the New York Times,1 described movingly, especially for a dog lovers, the lessons that he learned about his own illness from watching his beloved poodle, Bijou, behave as she went through her own health demise. Some of these lessons involved living in the moment and enjoying life’s simple pleasures. He also noted deeper insights about the ways animals’ brief lives inform us about our own mortality. Larger studies also point to cancer patients’ perception that their pets helped them cope with their illness and kept them healthier.2

A new initiative at the National Institutes of Health focuses on human-animal interactions and the ways they may influence health. Some of the priorities noted in the program announcement involve understanding the ways in which having pets in the home impacts children's social-emotional and cognitive development and how Animal-Assisted Interventions can be beneficial for those with intellectual, developmental, or physical disabilities.3 This new focus for investigation signals a prioritization of developing a solid research base that could lend further support to practices that are already in place, such as therapy dog visits to pediatric oncology units, or those that are thus far tested mainly in small, self-selected samples, such as animal assisted visits during chemotherapy-radiation treatments for those with head and neck cancer.4

In addition to paying more attention to how animals may have relevance for our health and well- being, researchers are also beginning to recognize the interconnectedness of human and companion animal health. Although epidemiological studies do not support the notion that there is an association between owning a dog, cat, or bird an lowered risk of cancer,5 the field of comparative oncology suggests that studying pets’ cancers may yield health benefits for humans in terms of drug development and even genetic markers.6 Similarly, obesity, a risk factor for cancer, is a problem for pets and their owners alike. Veterinarians and doctors are teaming up to better understand factors affecting both human and non-human animals in the same studies using a “One Health” perspective that considers the interplay of behaviors in companion animals and their owners.7 Researchers believe that leveraging the human-animal relationship can have success in addressing overweight and obesity in people and their pets, such as by encouraging walking if the motivation is partially based on keeping a beloved pet healthy. Our shared environments and intertwined lives also mean that insights gleaned about the biology of obesity in pets, as opposed to rodent models, may also have benefits for humans.

Other research in psychology that examines the fundamental processes of medical decision making also considers the human-animal bond. Not surprisingly, hypothetical decisions about treatment for human loved ones and beloved pets have been shown to show the same patterns, being influenced by level of closeness of the relationship and the severity of prognoses, attesting to animals’ valued place in our lives.8


1  Jennings, D. (2009, March 31). Life lessons from the family dog. New York Times, Retrieved from:

2 Larson, B. R., Looker, S., Herrera, D. M., Creagan, E. T., Hayman, S. R., Kaur, J. S., & Jatoi, A. (2010). Cancer patients and their companion animals: Results from a 309-patient survey on pet-related concerns and anxieties during chemotherapy. Journal of Cancer Education, 25, 396-400.

3  National Institutes of Health (2017, November 21). Human-Animal Interaction (HAI) Research (R01). Retrieved from:

4  Fleishman, S.B., Homel, P., Chen, M. R., Rosenwald, V., Abolencia, V., Gerber, J., & Nadesan, S. (2015). Beneficial effects of animal-assisted visits on quality of life during multimodal radiation-chemotherapy regimens. Journal of Community and Supportive Oncology, 13, 22-26.

5  Garcia, D.O., Lander, E. M., Wertheim, B. C., Manson, J. E., Volpe, S. L., Chlebowski, R.T., Stefanick, M. L., Lessin, L. S., Kuller, L. H., & Thomson, C. A. (2016). Pet ownership and cancer risk in the Women's Health Initiative. Cancer Epidemiology, Biomarkers & Prevention, 25, 1311-1316.

6  Jenks, S. (2015). Studying pets’ cancers may yield health benefits for humans. JNCI: Journal of the National Cancer Institute, 107, djv355

7  Bartges J., Kushner R. F., Michel, K. E., Sallis, R., Day, M. J. (2017). One Health solutions to obesity in people and their pets. Journal of Comparative Pathology, 156, 326-333.

8 Siess, S., Sikorski, L., & Moyer, A. (2018, April). Optimistic bias for negative prognostic information predicts hypothetical canine B-cell lymphoma treatment decision making. Poster to be presented at the annual scientific sessions of the Society of Behavioral Medicine, New Orleans, LA.