China has an aging population. As more and more only children leave to marry or work in another city, the elderly are left at home, alone and lonely. Many are turning to surrogate love from four-legged creatures. Eric Jou and Han Bingbin visit the world of the empty nesters and their beloved dogs.

On a cold winter's night in Beijing, five heavily bundled-up figures huddle in the brightly lit chamber housing a bank's 24-hour ATM machines. They are not contemplating an illegal heist, nor are they soliciting attention from passers-by. They are simply a gathering of old folks huddled together against the cold, waiting to walk their dogs and exchange gossip about their children, their pets and the latest health tonics for a long list of chronic illnesses that arrive with age.

In another corner of the parking lot in Dongcheng district, Zhang Fengru, 57, has brought her three dogs to socialize. Cradling a small Pomeranian bundled up in more sweaters than an Eskimo, Zhang looks happy as she watches her other dogs run around in circles.

"We come here every day, it's part of our nightly walk," says Zhang, gazing fondly at the dogs. "The animals all know each other and it gives me a chance to talk to my friends while our dogs get their exercise."

A total of 10 dogs from four owners are the regulars in this puppy party spot at the corner of Jiaodaokou and Gulou, and they are joined by occasional visitors and their canine pets on some evenings. Dogs of every breed, pedigree, size and age can be seen, but their owners are almost all elderly.

Zhang, who is retired from working in the oil industry, spends most of her day with her three dogs, which she fondly refers to as her own children even though she has offsprings of her own. When the topic of her two human children comes up, there is a flash of disappointment that flits across her face.

"Even though they live in Beijing, they never come and visit me. They're always too busy with this or that," Zhang says. "My dogs are closer to me than my children, they are here and my children are not."

Zhang is representative of a growing number of seniors in China who are empty nesters, with children who are grown and flown, or people who are now retired, and keeping pets for companionship. They seek solace and depend on their pets for company when they are lonely.

Fu Na, doctor of psychology at Beijing Normal University, says there are many benefits in old people keeping pets.

She says on the very basic level, caring for their pets forces the owners to exercise more, and find opportunities to socialize with other pet owners. The daily care that the pets demand, such as feeding, cleaning and grooming, prevents them from dwelling too much on their loneliness.

Fu says that the habit of referring to the dogs as their "son" or "daughter" is a surrogate situation that compensates for their missing children. Pets give unconditional love, and they do not answer back. Animals, especially dogs, are also nonjudgmental listeners.

"Raising pets can build an emotional connection that gives old people a complete sense of security," says Fu. "The pets are there to listen to their hopes, dreams, and even problems, and they do it by just being there."

Fu and her research team tracked more than 1,000 senior citizens in Beijing for half a year to find out more their well-being, such as their physical and psychological health. The subjects were divided equally into pet owners and non-pet owners.

Based on the results of the more than 700 questionnaires returned, Fu's study showed that pet owners are more likely to have better quality of daily life, with more social support, less chronic illness and require less medical treatment. More specifically, Fu's study points out that the longer someone keeps a pet, the better the quality of life.

A 66-year-old senior citizen living in by the Yonghegong area of Beijing who only gave his surname as Liu, bears testimony to the research results. Liu, a Beijing native, walks his pug Niu Niu along the park next to the Second Ring Road religiously every day. They can be seen walking every day - rain or shine - at about 6 pm and Liu says since he started having his dog, he has gone down three pant sizes and is feeling healthier and happier.

Liu is not exactly an empty nester although he sees more of the dog than his own son, who bought the pug but did not have time to look after it. As Liu's son became busier, Liu took over as the care-giver.

"Despite living with my son, I spend more time with the dog. I've raised it since it was puppy and it listens to my commands," says Liu.

Liu says Niu Niu has become like a second son, and the bond they share is a lifetime relationship. At one point, Liu thought about giving up the dog because he felt the pup was like a millstone, keeping him from traveling and leaving Beijing.

"Even if I did find a suitable person to take care of Niu Niu, I couldn't give him up," says Liu. "It is my duty to take care of it."

Liu's devotion is admirable and much mirrored in the bond that many other senior citizens share with their pets. But it can be a double-edged sword, says Fu Na.

She warns that raising pets may have troubling side effects. In her research, she discovered that pet-owners who choose to isolate themselves with their pets at home often cut-off other social interaction, which may lead to a "decrease in life satisfaction".

"It's especially dangerous for those who devote themselves to raising the pet," says Fu. "When it dies, it could take them at least half a year to - if they can - recover from the loss."

The sorrow can be overwhelming, as Lu Ling, 67, a veteran psychotherapist in Beijing says. She knows many cases and recounts an example of a couple who were grief-stricken when their dog died. Lu says it was obvious that the sorrow they felt was immense because although they tried to hide and pretend all was well, the pain was etched on their faces.

She also knows of another couple who had lost one of their four dogs. They became "an eccentric couple" who refused visits from acquaintances and seldom talked to neighbors.

"You can't rely on dogs to relieve the loneliness, old people should have a variety of recreation," says Lu. Nothing can replace human interaction, especially that between parent and child.

Lu is an empty nester herself, as her son works in the United States. But, she does not stay home with a pet, because she has none. She enjoys a healthy lifestyle - and spends her time visiting friends and relatives, travels and goes on vacation with her husband.

"These days, neighborhood communities offer diverse activities for old people such as dancing and singing, and there is a lot to do," she says. "Also, some seniors may have an expertise in specific fields which they can tap upon as a community volunteer, and share their wealth of knowledge with the younger residents."

Despite the double-edged nature of the bond between man and dog, some seniors value their relationships with their pets over the one they have with their children.

Chang Jixia, 52, part of the doggy group that meets in front of Jiaodaokou with Zhang Fengru, says that her dog is more like a son to her than her own son, who is 25 and still living at home.

"My son doesn't do anything for himself, he needs me to take care of him. It gets tiring," says Chang. "My Wangzai doesn't want anything from me, and he's so happy to see me all the time. He feels more like a son to me."

Wangzai, Chang's Yorkshire terrier, is 5 years old now. He was adopted a few years ago and he hasn't left Chang's side since. Chang says when she first got the puppy, he was very sickly and his legs couldn't hold him and he had breathing problems. At one point, Chang says, she had to give him mouth-to-mouth resuscitation.

Over the years she has spent a lot of money on Wangzai and her other dog, a Pomeranian - money on food, hygiene, medical care, money which she says is well spent. Fellow dog lover Zhang agrees.

Zhang's own dog, Qiu Qiu, a rescued stray, was diagnosed with a lung infection a few years ago. Now with every breath he takes, he releases a crackling wheeze. Wrapped in a pint-sized down jacket with matching beanie, the chestnut-colored Pomeranian is costing Zhang upwards of a few thousand yuan a year just to keep him breathing.

Over at the Yu Kang Animal Hospital in the Sihui area of Beijing, investor and veterinary assistant Sun Jiayin, 29, has seen the effect that pets have on senior citizens.

Sun says seniors take much better care of their dogs than the young people and are more responsible when it comes to animal care.

"If an animal is sick, a senior owner would definitely take the animal to the hospital, whereas a younger person may try to wait it out," she notes.

"These days there are many older owners, and the prospect of the animal passing away is very daunting. Most will bury the animal or have some kind of ceremony. They may then buy or adopt another animal because they have become accustomed to having an animal companion."

Even though she knows she will probably outlive Qiu Qiu, Zhang says she will still care for the dog whole-heartedly. To Zhang, her dogs are part of her life and if they should pass away it will be unbearable, but she is not closed off to the idea of raising a new stray she finds on the street.

"Dogs are very loyal. They know if someone is kind to them, they will be loyal forever," Zhang says. And often, they love back more than the children do.