The decision, announced earlier this week, has inspired several animal lovers to round up and save as many of the dogs as possible. Russian billionaire Oleg V. Deripaska is funding a "dog rescue" golf cart that's now scooping up dogs around Sochi.
"People aren't tolerant of [killing], and now you have the world audience coming to your doorstep," said Kelly O'Meara, a director at Humane Society International.
There are "much more effective ways they could have handled this," such as spaying and neutering the animals, she said.
But the Russian resort on the Black Sea isn't the only place with a dog problem. An estimated 250 to 300 million stray dogs roam our planet, according to O'Meara.
It's easy to confuse a stray dog with a pet, especially in non-westernized countries, added Matt Gompper, a professor of mammalogy at the University of Missouri who edited the book Free-Ranging Dogs and Wildlife Conservation.
For instance, some cultures view pet dogs in a way that's analogous to how Americans see barn cats: A person might feed and house a dog and sometimes give it veterinary care, but the animal still roams as it pleases. (See "5 Amazing Stories of Devoted Dogs.")
"It's a very different concept of ownership, even though all of the dogs are entirely dependent on human resources," Gompper said.
Other dogs are truly strays, hanging around a neighborhood and begging for food. Unlike cats, free-roaming dogs aren't really feral, since they rarely hunt wildlife. (Also see "Writer's Call to Kill Feral Cats Sparks Outcry.")
Some stray dogs—especially those shunned or treated inhumanely—band together into packs for safety and food, avoiding people. But most stray dogs are actually not menacing, because most rely on the public for their food—"positive interaction is necessary for them to get what they need," O'Meara said.
Countries differ in how they deal with stray canines, but generally there are three main methods: killing, mass sheltering, and sterilization and vaccination, O'Meara said.
Indonesia, Malaysia, Kenya, Egypt, Russia, and much of eastern Europe and the Baltic countries have mass dog-killing programs. Many such initiatives are put in motion after an outbreak of disease, such as rabies, that's a threat to human health.
The most common form of killing stray dogs is poisoning, a "silent killer" that is being used in Sochi, O'Meara said.
Usually, meat is laced with strychnine, a common poison, and put out on the street for whatever animal might find it—mostly dogs. A poisoned dog can "take up to an hour to die—it's horrific and extremely painful for an animal to go through," she said. After the animals die, the extermination service picks up the carcasses at night.
Other methods include shooting, bludgeoning, or gassing, practices that are often achieved by rounding up large groups of dogs.
According to O'Meara, mass killing is not only inhumane but also ineffective, since the dogs that extermination services catch are usually the animals least afraid of people. The shyest and possibly the sickest dogs aren't caught, which may increase the threat to public health from bites and disease transmission.
This approach—common in Thailand, India, and Italy—takes street dogs and puts them into huge shelters, which are often not equipped to handle the high populations.
Conditions are often poor, and many of the captured dogs have more puppies, only worsening the problem.
Dogs in mass shelters usually live their whole lives in the facilities.
Sterilization and Vaccination
In western Europe, Bhutan, the Philippines, India, Nepal, Costa Rica, Chile, Panama, South Africa, and Mauritius, stray dogs are sometimes sterilized and immunized, then released back into cities.
Since stray dogs are often a public health concern, governments mostly fund these programs with startup assistance from animal groups like the Humane Society. (See dog pictures submitted to National Geographic.)
Advocates of this approach say that packs of stray dogs will eventually die off because they can't reproduce, and in the meantime are not at risk of spreading diseases like rabies (vaccinated dogs are marked by a small notch in their ears).
According to O'Meara, in places where sterilization and vaccination programs have been put in place, the dogs overall act calmer.
For instance, neutered males fight less over females, causing less injury to females and wreaking less havoc among the dog population.
Religion is often a factor in how dogs are treated: the Buddhist nations of Thailand and Bhutan have traditionally avoided killing dogs, while Islamic countries usually adopt the practice. But even that is changing. (Take National Geographic's dog quiz.)
Dhaka, the capital of Bangladesh, is the first Islamic city to take on mass sterilization and vaccination, "and the hope is to spread to the rest of the country," she said.
However, Gompper noted that vaccination can be wasteful, since many dogs have already been exposed to diseases like parvovirus and have an immunity to them.
Some countries will also round up their dogs and dump them somewhere else, which is a short-term solution, Gompper added.
Stray dogs can also end up in smaller municipal shelters, which is common in the U.S. In much of the Caribbean, such as Trinidad and Tobago and Puerto Rico, dogs end up in small shelters, but adoptions are low, so the animals are often euthanized.
Humane Society International's O'Meara said that the organization encourages adoption. (See "Can Dogs Feel Our Emotions? Yawn Study Suggests Yes.")
Yet adopting animals is a concept foreign to many cultures, noted Gompper, especially in Asia where dogs might be perceived as dangerous or diseased: He described how a visiting Indian colleague was taken aback to see a dog on his living room couch.
"Not surprisingly, there are going to be barriers against shifting toward a culture of adopting dogs," he said.
However, the idea of a dog in the home has made inroads into some countries, including the Chinese, who were once more likely to eat dogs than keep them as pets. Thanks to an interest in house pets in rapidly developing China, more stray dogs are being adopted there, O'Meara said.
Humane Society International is training many vets abroad to catch dogs without hurting them and teaching best practices for spaying and neutering and humane euthanasia. In the Philippines, veterinarian Alice Utlang has even pushed the city of Cebu to switch from killing dogs with gas chambers to using the less painful method of sodium pentobarbital.
Overall, despite the fact there are a billion dogs on Earth, Canis familiaris is a species we still don't understand. For instance, little is known about domestic dogs, in particular how they act in their environment, and with us.
This needs to change, since no one knows the risks of having so many of these "wolves in domesticated clothing" in our midst, Gompper said.
"There are implications we haven't thought through."