The subject of our survey is the impact of dog ownership on health, medical needs, physical activity, quality of life, and social contacts in elderly people.

The United Nations has noted a risk in the ageing of populations in such countries as e.g. Europe, Australia, North America, New Zealand, and Japan [1] . The percentage of the population over 65 years of age will rise in these countries over the next 15 years. Whereas in 2010, in a group of 100 people, 30 belonged to the age group of 25 - 64 years, by 2030 this number will climb to 46 [1] . Given this situation, the question evolves how owning a dog can help promote independence and health among the elderly.

Friedmann noted a significant reduction in the mortality of patients with chronic heart disease [2] [3] , and Ruzic demonstrated that regular dog-walking improved physical capacity [4] . Dog ownership is credited with lowering blood pressure [5] - [9] and resting heart rate [8] , a phenomenon which is intensified when a dog is pet [10] . The variability in heart rate rose significantly [11] and a prophylactic effect for heart health (evidence level B) was confirmed [12] .

Regular, moderate exercise several times per week plays an essential role in preventive healthcare [13] - [15] . However, the percentage of people over the age of 60 in Germany who were inactive in 2012 was 34% for men and 40% for women [16] . In the European average, 59% of women and 53% of men over the age of 55 are never physically active [17] , in Australia, just under one third [18] , in the USA more than 35% [19] .

The survey was conducted of residents over 65 years of age in a rural community, Sauerlach, near Munich. Participants were acquired by means of a call to the public.

From Feb. 23rd to June 6th 2012, fifty-two persons (Table 1) took part in the study and were interviewed personally.

Cat owners were allocated to the group of people who did not own a dog. Due to the major difference between dog and cat owners, the analysis of cat owners is added as a separate text passage following the analysis of dog owner and those who do not own a dog.

In a one-on-one interview based on a questionnaire, participants were interviewed at home about their lifestyle, quality of life, social life, weight, height and various complaints and diagnoses. The BMI (Body-Mass Index) was also calculated.

Using the W-5 from the WHO [20] , depressive symptoms were determined, a score below 13 points or 52% can indicate depression.

Statistical calculations, e.g. the t Test were conducted using http://graphpad.com/quickcalcs and the Pearson correlation with the help of Microsoft Excel and the online calculator at http://vassarstats.net.

Prior to conducting the study, it was expected that dog owners would be the more active, healthier participants. Surprisingly, those who do not own dogs appear to be in some cases healthier and more vital; they reject dog ownership to maintain their personal freedom and to stay flexible. Raina confirms this phenomenon [21] , Burns also mentions economic reasons [22] .

The present study makes no claim to general validity, but is a random sampling to compare with other studies. Weaknesses in the present study are the number of participants (n = 52) and the collection of data provided by participants during an interview. Many authors have also mentioned these problems [23] - [28] .

Dog owners who walk their dogs got significantly more exercise which confirms studies of dogs and the elderly [23] [29] - [36] , but also of dogs and people of all ages [7] [23] [37] - [46] . The dog owners in this study exceeded by far the WHO recommendations for people over the age of 65 in regard to physical activity to maintain health by an average of 2.5 hours (=150 minutes) of physical activity or more per week [15] . Australian studies challenge the connection between dog ownership and the resulting health benefits [47] [48] . The Australian lifestyle seems to be different than in Germany and it is less usual to walk with the dog.

A lack of exercise is a widespread health risk in industrialized countries. The increase in movement due to the dog is an important prophylaxis against cardiovascular diseases [49] , which is a frequent reason for hospitalizations [50] . Movement also prevents diabetes, intestinal cancer and age-related falls [51] and even has a positive effect on arthrosis [52] .

One explanation for the strong effect of the dog on the owner’s physical activity could be that Germany is densely populated and life is extensively regulated and the dog in more populated regions must be walked on a leash during the multiple daily walks. Consequently, the impact of a dog on the owner’s physical activity in Germany is to be rated as especially intensive in an international comparison. In this respect, it was clear that dog owners and cat owners cannot be compared, as confirmed by Thrope and Serpell [23] [46] [53] so that a comparison of pet owner and those who do not have a pet does not appear to make much sense without differentiation of the type of pet.

The statements on the subject of a move to an assisted living facility were very clear. A move would only be considered if the dog or cat could be taken along.

In this case, more offerings should be made available in the retirement home sector for residents with dog and other pets to provide those affected with alternatives, particularly if owners are overwhelmed by the care of the pet because of their frailty or dementia and an attempt to provide care would jeopardize the owner and/or the animal. This could allow pet owners to keep their “friend” and still go to a care environment.

Dog owners had on average more internal medicine diagnoses and took just as much medication as those who did not own a dog; back and joint pain was less frequent, as Serpell also confirms [54] ; the quality of life was higher on average, even though the percentage of depressed individuals was just as high as among those who did not own a dog. Friedmann discovered more depressed individuals in the group of those who did not own dogs [55] . Other studies noted a higher level of satisfaction and stability among dog owners [36] and fears were significantly lower [46] . Dog owners feel significantly safer with the dog [56] .

These positive mental effects could be based on the intensive connection to the dog. This tie is closer than to other pets as indicated by the selection of the place to sleep and how the dog is treated. This was also described by other authors [56] [57] . In the event of a death, the dog was a comfort to the majority, which confirmed the results of Akiyama [58] .

Dog owners went to the doctor much less frequently; in Siegel, the comparison of dog owners to those with no dog was significant. The comparison of pet owners to dog owners was not [56] [59] .

Dog owners also had more frequent contact to the social environment and were less reserved than those who did not own a dog. The dog was an effective catalyst to establish contact, which other authors also described [36] [46] [60] . Good social ties are extremely important, particularly at an advanced age. The larger the social network is, the less loneliness and the less mental decline [61] which is encouraged by loneliness and social isolation are [62] .

The positive effect of a dog could have positive effects from a national economic point of view because cardiovascular health is an important predictor of independence and health into old age.

Much research has been done on the subject “pets and the elderly”, but little attention has been given to the topic “dogs and the elderly”. The difference between a dog and other pets is so great that pet owners and those who do not own pets are not comparable. Additional research needs to be done, if possible with larger study groups or the question of the connection between dog ownership and hospitalizations and long-term studies dealing with the need for care in later life.

The published results are part of the thesis by Anne Poestges “Einfluss eines Haustieres auf körperliche Aktivität, Selbständigkeit, soziale Einbindung, Gesundheit und Lebensqualität älterer Menschen am Beispiel des Hundes” at the Medical Faculty of the Ludwig-Maximilians University of Munich (submitted).

Anne Poestges,Ursula Gresser,Barbara Maria Richartz, (2016) The Impact of a Pet, in This Case a Dog, on Physical Activity, Independence, Social Contacts, Health and Quality of Life of Elderly People. Advances in Aging Research,05,83-95. doi: 10.4236/aar.2016.54009