Research shows that owning a pet can bring health benefits.
We tend to think of dogs and cats as enriching the lives of children. But many adults without children also own pets. In fact, the majority of American households have at least one dog or cat, and most people say that the love and companionship their animals provide more than offsets the cost of food and other expenses involved in maintaining the health of a furry or feathery friend. Now, scientists have found a surprise bonus in possessing a Rover or a Tabby: improved health, including a reduced risk of heart disease.
Study reveals lowered blood pressure
Three studies in the 1990’s have investigated whether pets provide their owners with health benefits. The first study, reported in 1992, looked at blood pressure levels and levels of cholesterol and triglyceride fats in the blood of pet owners and nonowners. The researchers, Warwick Anderson and colleagues at the Baker Medical Research Institute in Australia, questioned 5,741 men and women attending a heart disease risk clinic on their lifestyle and whether they had a pet. Then, they compared screening-test results of the pet owners with the test results of the nonowners. High blood pressure and high blood levels of cholesterol and triglycerides put people at a greater-than-average risk of a heart attack.
The 784 people who owned pets, particularly the men, had significantly lower blood pressure and lower levels of triglycerides and cholesterol than the men and women without pets. On average, men who owned pets had triglyceride levels that were 13 percent lower than those of men without pets. If these low levels had been found only among dog owners, it could be assumed that exercise in the form of walking the dog had influenced the results. But the dog owners and the owners of other pets had similar test results. Owning a pet, the researchers said, was as effective in lowering blood pressure as switching to a low-salt diet or reducing alcohol consumption.
A variety of health benefits
A second 1992 study evaluated the effect of owning a dog or cat on its owner’s health over a period of months. James Serpell at Cambridge University in the United Kingdom recruited three groups of people who did not own a pet. They all completed questionnaires on the frequency of minor health problems, such as headaches, difficulty sleeping, and indigestion. One group then received dogs, the second group received cats, and the third group had no pets.
The three groups began the study with no significant differences in their scores on the health questionnaire. Differences began to appear after one month and continued throughout the 10-month study. The two groups with pets reported that their general health had greatly improved, though the group with dogs fared slightly better than the group with cats. And dog ownership also meant that people got more exercise than they previously had.
Serpell’s research continued in 1994 in an effort to find out if the results would hold up over a longer period of time—18 months—and among larger groups. Early results confirmed his original findings.
Benefits to the elderly
The third study of the health benefits of pet ownership concentrated on older people. It involved the number of medical visits made by almost 1,000 people covered by Medicare, the federal health insurance program for people receiving social security benefits. The research was reported in 1991 by epidemiologist Judith Siegel of the University of California at Los Angeles.
Siegel interviewed the participants by telephone every two months for one year. At the end of that time, she found that pet owners had reported fewer visits to the doctor than nonowners. While participants in general saw a doctor more often during stressful times—for example, after the death of a relative or friend—dog owners reported fewer such visits.
Like Serpell, Siegel found increased recreational walking among dog owners. She reported that dog owners spent an average of 1.4 hours each day outdoors with their dogs. Even cats appeared to motivate some owners to be more active than people without an animal companion.
Good for the body and soul
Increased physical activity can translate into improved health in several ways: by strengthening the heart muscle and improving blood circulation and by slowing the loss of bone tissue that commonly accompanies aging. Thus, the capacity of a dog to motivate a person to increase outdoor activity may be one of the most important contributions dogs make to human health.
In addition to improving an owner’s physical health, animals contribute to a sense of psychological and social well-being. And this sense of well-being may account for some of the improvements in physical health reported by various researchers throughout the 1980’s. These included drops in pet owners’ blood pressure when the pet was present, presumably because the pet had a soothing effect.
Other research in the 1990’s has investigated the power of pets to relieve stress. For example, in 1991, Karen Allen and her colleagues at the State University of New York at Buffalo monitored women who were attempting to solve arithmetic problems. She then had friends of the participants sit in on the problem-solving sessions. This increased stress and resulted in fewer correct answers than when the women worked alone. Finally, Allen brought in the participants’ dogs. The women’s stress levels dropped, even though they continued to work on challenging arithmetic problems.
A buffer against loneliness
Other studies have shown that animals are buffers against ongoing problems, such as loneliness. An older person who lives alone, for example, may be vulnerable to loneliness or depression. Peter Peretti at Richard J. Daley College in Chicago found in 1990 that a majority of 128 older dog owners living alone reported that their dog was their only friend. And a 1986 study by John Goldmeier at the University of Maryland in Baltimore found that among 116 older women living alone, those who had pets showed a greater sense of well-being as measured by four criteria: absence of agitation, degree of optimism, absence of loneliness, and ability to think of the future.
Older people become especially vulnerable to isolation and depression after the death of a spouse. In 1989, a research group headed by Thomas Garrity at the University of Kentucky College of Medicine in Lexington found that bereaved people who had a strong attachment to a pet rarely suffered from depression, even when they lacked close friends.
Since 1988, I and my colleagues at the Center for Animals in Society at the University of California at Davis have concentrated on the socializing role of pets. In one study of older pet owners, we found that all the dog owners talked to their pets during regular walks. They often spoke to other people during these walks, focusing primarily on their dogs but also conversing on current, rather than on past, events. And neighbors stopped to talk about the dog whether the dog was present or not.
Another of our studies of older pet owners revealed that even a pet rabbit or turtle attracted adults and children who initiated conversations, though they had never met the owner. These socializing effects also applied to pet owners with disabilities. Many people feel awkward about striking up a conversation with someone in a wheel-chair. But we found that people often spoke to children and adults in wheelchairs who also had dogs.
Beware of bites
Animal companions also present some risks to the owner. Some animals bite, and pets can also transmit disease-causing viruses, bacteria, parasites, and fungi to people.
Bites are most commonly inflicted by dogs, but cats also bite. Bites pose a double threat. First, the wound itself can be painful and may require stitches. Second, infectious microbes can enter the wound from the animal’s saliva and cause illness.
Dog bites can be prevented by selecting a breed known to be nonaggressive. However, if a dog behaves in an aggressive manner, immediate steps should be taken to thwart the behavior, such as giving the animal obedience training.
Pets can also transmit diseases to people without biting them. One way is through their waste. Gastrointestinal diseases caused by bacteria can be transmitted to people in the feces of infected dogs, birds, and aquarium pets such as frogs and reptiles. Cats can carry protozoa that cause toxoplasmosis. This flulike disease is very serious in a pregnant woman, because it can lead to mental retardation, blindness, and other birth defects. People may be infected if they do not wash their hands after cleaning an infected cat’s litter box.
People can contract other diseases by touching an infected animal. Tularemia, a bacterial infection also known as rabbit fever, is transmitted directly through the skin by handling an infected animal or being bitten by it. Ringworm, a common fungal infection of dogs and cats, is easily acquired by touching the characteristic red, scaly rings on the animal’s skin. By inhaling dust or bird excrement from the cage of an infected bird, people can develop psittacosis, a lung infection spread by parakeets, parrots, and canaries.
In some areas of the United States, people can get diseases carried by ticks that pets pick up from wild animals. Lyme disease and Rocky Mountain spotted fever are both transmitted through tick bites. And fleas are more than an itchy nuisance to Rover and Tabby: They can spread tapeworm or even bubonic plague in some areas of the country.
People also can become hosts to common parasites of dogs. Mites can burrow into human skin and bring on a rash, hair loss, and itching. Hookworms and roundworms from puppies can invade the human digestive tract.
In general, getting a disease from a pet poses a health risk primarily to children, pregnant women, the elderly, and people who have weakened immune systems. But the risks can be made negligible by observing reasonable hygiene, avoiding situations that provoke an animal to bite or scratch, and keeping the animals’ veterinary care and vaccinations current. Such good friends deserve good care indeed.