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Chapter 5

The Triple Threat: How Stress, Isolation, and Lack of Physical Activity Affect Us All

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More than 30 million Americans take antidepressants: See the Center for Disease Control and Prevention’s website on the subject at

Insomnia afflicts about one-fourth of American adults: See the National Sleep Foundation at

feeling lonely, and only around half of us report having meaningful, in-person social interactions: See “The ‘Loneliness’ Epidemic” at the Health Resources and Services Administration, Also see Elena Renken, “Most Americans Are Lonely, and Our Workplace Culture May Not Be Helping,” Health News from NPR, January 23, 2020.

only 8 percent of adolescents get the recommended sixty minutes of exercise daily, and less than 5 percent of adults get the recommended thirty minutes: See the US Department of Health and Human Services’ “Facts & Statistics” on physical activity at

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walking approximately three and a half miles a day for women and approximately 7 miles for men: See Barbara King, “The Anthropology of Walking,” NPR, January 9, 2014.

sedentary behavior is linked to premature death from all causes: See Aviroop Biswas, et al., “Sedentary Time and Its Association with Risk for Disease Incidence, Mortality, and Hospitalization in Adults: A Systematic Review and Meta-analysis,” Ann Intern Med 162, no. 2 (January 2015): 123–32. doi: 10.7326/M14-1651.

getting up from a chair every hour for two minutes of light activity: See Srinivasan Beddhu, et al., “Light-intensity Physical Activities and Mortality in the United States General Population and CKD Subpopulation,” Clin J Am Soc Nephrol 10, no. 7 (July 2015): 1145–53. doi: 10.2215/CJN.08410814. Epub 2015 Apr 30.

physical activity has been shown to lower the risk of many types of cancer: See the National Cancer Institute’s page on physical activity and cancer at,

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up to 70 percent of behavioral problems in dogs are attributable to some form of anxiety: See Katriina Tiira, Sini Sulkama, and Hannes Lohi, “Prevalence, Comorbidity, and Behavioral Variation in Canine Anxiety,” Journal of Veterinary Behavior 16 (November–December 2016): 36–44.

leisure-time exercise significantly reduces the risk of depression: See Samuel B. Harvey, et al., “Exercise and the Prevention of Depression: Results of the HUNT Cohort Study,” Am J Psychiatry 175, no. 1 (January 2018): 28–36. doi: 10.1176/appi.ajp.2017.16111223. Epub 2017 Oct 3.

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“enhancing physical activity may be an effective prevention strategy for depression”: See Karmel W. Choi, et al., “Assessment of Bidirectional Relationships Between Physical Activity and Depression Among Adults: A 2-Sample Mendelian Randomization Study,” JAMA Psychiatry 76, no. 4 (April 2019): 399–408. doi: 10.1001/jamapsychiatry.2018.4175.

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“Exercise is the closest thing to a wonder drug”: See Aaron E. Carroll, “Are You Sitting Down? Standing Desks Are Overrated,” New York Times, November 20, 2018, Section B, Page 3.

The bestselling author of Inside of a Dog: What Dogs See, Smell and Know: See Alexandra Horowitz, Inside of a Dog: What Dogs See, Smell and Know (New York: Scribner, 2009).

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a significant correlation between anxiety and impulsivity, and premature muzzle graying in young dogs: See Camille King, Thomas, J. Smith, Temple Grandin, and Peter Borchelt, “Anxiety and Impulsivity: Factors Associated with Premature Graying in Young Dogs,” Applied Animal Behavior Science 185 (December 2016): 78–85.

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hiding or running away, and elevated cortisol levels in the dog’s fur: See M. Siniscalchi, et al., “Cortisol Levels in Hair Reflect Behavioral Reactivity of Dogs to Acoustic Stimuli,” Res Vet Sci 94, no. 1 (February 2013): 49–54. doi: 10.1016/j.rvsc.2012.02.017. Epub 2012 Mar 24.

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“the non-specific response of the body to any demand made upon it”: For a current overview of stress, see Lívea Dornela Godoy, et al., “A Comprehensive Overview on Stress Neurobiology: Basic Concepts and Clinical Implications,” Front Behav Neurosci 12, no. 127 (July 2018): 127. doi: 10.3389/fnbeh.2018.00127. eCollection 2018.

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Selye highlighted the impact that everyday life and experiences can have not only on our emotional well-being but also on our physical health: Siang Yong Tan, and A. Yip, “Hans Selye (1907–1982): Founder of the Stress Theory,” Singapore Med J 59, no. 4 (April 2018): 170–71. doi: 10.11622/smedj.2018043.

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when you’re stressed, your dog is probably stressed, too: See Milla Salonen, et al., “Prevalence, Comorbidity, and Breed Differences in Canine Anxiety in 13,700 Finnish Pet Dogs,” Sci Rep 10, no. 1 (March 2020): 2962. doi: 10.1038/s41598-020-59837-z.

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Sleep spindles are how we, and our dogs, consolidate our memories: See Ivaylo Borislavov Iotchev, et al., “Averaging Sleep Spindle Occurrence in Dogs Predicts Learning Performance Better than Single Measures,” Sci Rep 10, no. 1 (December 2020): 22461. doi: 10.1038/s41598-020-80417-8. For everything you want to know about sleep, see Matthew Walker’s book Why We Sleep: Unlocking the Power of Sleep and Dreams (New York: Scriber, 2017).

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clues to a bidirectional interaction between the brain and gut bacteria: See Y. Sudo, et al., “Postnatal Microbial Colonization Programs the Hypothalamic–Pituitary–Adrenal System for Stress Response in Mice” J Physiol 1 (2004): 263–75. For a general overview of the gut-brain axis with references for further reading, see Natasha Bray, “The Microbiota–Gut–Brain Axis,” Nature Research, June 17, 2019,

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researchers sampled gut bacteria from 31 dogs confiscated from a home where they were made to fight in a dog-fighting ring: See Nicole S. Kirchoff, Monique A. R. Udell, and Thomas J. Sharpton, “The Gut Microbiome Correlates with Conspecific Aggression in a Small Population of Rescued Dogs (Canis familiaris),” PeerJ 7 (January 2019): e6103. doi: 10.7717/peerj.6103. eCollection 2019.

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dogs fed raw diets have a more balanced growth of bacterial communities and an increase in fusobacteria: See M. Schmidt, et al., “The Fecal Microbiome and Metabolome Differs Between Dogs Fed Bones and Raw Food (BARF) Diets and Dogs Fed Commercial Diets,” PLoS ONE 13 (2018): e0201279. doi: 10.1371/journal.pone.0201279.

raw diet for at least one year were shown to have a richer and more even microbiome compared to kibble-fed controls: J. Kim, et al., “Differences in the Gut Microbiota of Dogs (Canis lupus familiaris) Fed a Natural Diet or a Commercial Feed Revealed by the Illumina MiSeq Platform,” Gut Pathog 9 (2017): 68. doi: 10.1186/s13099-017-0218-5.

pave the way for increased secretion of the “happy hormone” serotonin (healthier gut-brain axis): See M. Valles-Colomer, et al., “The Neuroactive Potential of the Human Gut Microbiota in Quality of Life and Depression,” Nature Microbiology 4 (2019): 623–32.

Actinobacteria, which is associated with cognitive decline and Alzheimer’s disease in dogs and humans: See Eniko Kubinyi, et al., “Gut Microbiome Composition is Associated with Age and Memory Performance in Pet Dog,” Animals (Basel) 10, no. 9 (August 2020): 1488. doi: 10.3390/ani10091488.

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a fancy name for a fecal transplant: For access to a library of current studies on this procedure, see Open Biome’s list at

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when an intestinal barrier is compromised, it can lead to a spectrum of health challenges: See Michael Camilleri, “Leaky Gut: Mechanisms, Measurement and Clinical Implications in Humans,” Gut 68, no. 8 (August 2019): 1516–26. doi: 10.1136/gutjnl-2019-318427. Epub 2019 May 10.

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we often suspect dysbiosis and leaky gut as the root cause: See Rachel Pilla and Jan S. Suchodolski, “The Role of the Canine Gut Microbiome and Metabolome in Health and Gastrointestinal Disease,” Frontiers in Veterinary Science 6 (January 2020): 498. doi: 10.3389/fvets.2019.00498. eCollection 2019.

dysbiosis is associated with obesity, metabolic diseases, cancer, and neurological disfunctions, to name a few: See I. N. Kieler et al., “Gut Microbiota Composition May Relate to Weight Loss Rate in Obese Pet Dogs,” Vet Med Sci 3 (2017): 252–62. doi: 10.1002/vms3.80. Also see J. A. Montoya-Alonso, et al., “Prevalence of Canine Obesity, Obesity-related Metabolic Dysfunction, and Relationship with Owner Obesity in an Obesogenic Region of Spain,” Front Vet Sci 4 (2017): 59. doi: 10.3389/fvets.2017.00059. Also see L. Zitvogel, et al., “Anticancer Effects of the Microbiome and Its Products,” Nat Rev Microbiol 15 (2017): 465–78. doi: 10.1038/nrmicro.2017.44. Also see J. Wu, et al., “Intestinal Microbiota as an Alternative Therapeutic Target for Epilepsy,” Can J Infect Dis Med Microbiol 2016 (2016): 9032809. doi: 10.1155/2016/9032809.

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Raw food appeared to activate the expression of genes that had anti-inflammatory effects: Johanna Anturaniemi, et al., “The Effect of Atopic Dermatitis and Diet on the Skin Transcriptome in Staffordshire Bull Terriers,” Frontiers in Veterinary Science 7 (2020). doi: 10.3389/fvets.2020.552251.

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launched the Canine Healthy Soil Project

the power of so-called nature therapy: See Margaret M. Hansen, Reo Jones, and Kirsten Tocchini, “Shinrin-Yoku (Forest Bathing) and Nature Therapy: A State-of-the-Art Review,” Int J Environ Res Public Health 14, no. 8 (July 2017): 851. doi: 10.3390/ijerph14080851.

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animals know there’s an earthquake coming before it happens: See Masashi Hayakawa, “Possible Electromagnetic Effects on Abnormal Animal Behavior Before an Earthquake,” Animals (Basel) 3, no. 1 (January 2013): 19–32. doi: 10.3390/ani3010019.

daily ANS activity in mammals responds to changes in geomagnetic and solar activity: See Abdullah Alabdulgader, et al., “Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment,” Sci Rep 8, no. 1 (February 2018): 2663. doi: 10.1038/s41598-018-20932-x.

Animals are especially sensitive to Schumann resonances: See Miroslaw Kozlowski and Janina Marciak-Kozlowska, “Schumann Resonance and Brain Waves: A Quantum Description,” NeuroQuantology 13, no. 2 (May 2015). doi: 10.14704/nq.2015.13.2.795.

When biorhythms were disrupted, confusion and agitation were some of the first symptoms: See Ryan W. Logan and Colleen A. McClung, “Rhythms of Life: Circadian Disruption and Brain Disorders Across the Lifespan,” Nat Rev Neurosci 20, no. 1 (January 2019): 49–65. doi: 10.1038/s41583-018-0088-y.