It has to be vomit. Nothing else could explain that wet, meaty stench wafting from the back seat. Pulling the car to a stop, I look back at my dazed seven-month-old golden retriever, Dublin, then down at what is indeed a small but pungent pile of partially digested kibble that a 90-minute car trip has sent rocketing up from her motion-sensitive stomach and onto the car's upholstery.

To make matters worse, the egg-shaped "Tamagotchi" toy in my pocket lets out a familiar "beep-bop-beep" to announce that that "Mametchi," the smiling bearlike character on the screen of the handheld device, has taken a digital dump on its virtual carpet. At this point, I don't even want to check on my FooPet and my iPuppy because I know they both need virtual walks, virtual baths and virtual vet appointments. It seems that between my very real pet and the three computerized ones I recently "adopted," my job as dookie-cleaner-in-chief has multiplied exactly threefold.

Scrubbing up Dublin's puke takes several paper towels, some all-purpose cleaner and a dab of elbow grease. Mametchi's steamer requires nothing more than the touch of a button. As I finish, however, my now perky real dog decides I've done an exemplary job and manically licks my face in what I can only imagine is gratitude. Mametchi doesn't lick my face. Instead it declares: "Bleep bleep!" Translation: "All this pooping has now made me hungry."

Pressing Mametchi's food button and giving Dublin a pat on the head, I climb back into the driver's seat and continue pondering the question I've set out to answer: Which is better—a living, breathing, puking, licking pet or a beeping, battery-powered, wirelessly enhanced virtual pet? The answer, I think, will take some advice from smarter folks than me.

Of Mutt & Mouse

The world of virtual pets today is a multibillion dollar industry with millions of users in scores of countries. The pets are generated by software and hardware-based programs that empower users to create their perfect pet, care for it as much as they want and neglect it whenever it becomes inconvenient. A virtual pet doesn't chew up your socks or eat your homework. It doesn't cost a fortune in vet bills when it swallows a bottle of antacids and, in most cases, it will never die.

Not everyone, however, thinks that owning a digital pet is pleasurable or even healthy. And in one case, a top scientist who has studied the subject extensively says virtual pets pose a real threat to society.

So where did it all start? By most accounts it was in 1986, with a little game for the Macintosh called Puppy Love.

"We thought Puppy Love would be an educational game that could be a model for teaching [computer] programming," says Tom Snyder, the creator of Puppy Love, a mind-bogglingly simply game that features a Stephen Hawking–esque narrative voice and involves trying to teach a grayscale puppy tricks using keystrokes. "What we got instead was really just a delightful game that kids and parents could play together. I have a lot of doubts about games for kids these days. I think to do a simulation of something that doesn't need to be simulated and to market it as something with moral value is wrong. It's entertainment, pure and simple."

The virtual pet games of today are exponentially more sophisticated than in Snyder's day. The Tamagotchi I have (usually referred to as just a "Tama") has removable cartridges that can load new characters and programs. It also has an online community called TamaTown where users can log on, introduce their Tamas to other Tamas, play games and talk with fans from around the world.

The iPuppy application for my iPhone brings up an adorable husky puppy that scampers about, barking and playing in a 3-D world that goes wherever I do. And my FooPet account features countless breeds of realistic dogs, each capable of tracking how happy it is through the amount of online attention I give it. In addition there are intricate games like Render Ranch that use breeding and genetics as a basis for play, allowing users to create entire farms using complex breeding schemes and business-based approaches.

Fred Bairn, a computer programmer in Snowflake, Ariz., and the creator of Render Ranch, disagrees with Snyder that virtual pet games can't be educational. He says his game is exactly that.

"We have normal everyday people on the site as well as real ranchers and breeders," he says. "We try to provide an educational game. Something that's fun, but something they can learn skills that they can use in real life."

Pay to Play

Besides the subscription fees that some sites charge people to adopt virtual creatures, users also spend millions of dollars on virtual goods to pamper their pets. The virtual-goods industry not only includes virtual pet products, but also "gifts" on Facebook like "Pink Cadillacs" and accessories for World of Warcraft–style role-playing games like Celestial Steed. All told, the virtual-goods industry brought in just over $1 billion in the United States in 2009 and $7 billion in Asia according to market research firms Inside Network and Inside Virtual Goods; and fake pet products, no doubt, made up a large portion of that total.

Danny Nguyen, a 22-year-old student, says he spends about $10 to $20 per month on things like "morph potions" and "magic robes" for his bunny character for the site Neopets, one of the most popular virtual pet sites around, boasting some 25 million users. He doesn't view the money spent as any kind of waste. In fact, he says that if he had more income he'd spend even more.

"It's not like you don't get something for your money," he says. "It's like buying action figures or something else that I don't really need but really want."

Others like Kim May, a 51-year-old former dog breeder from Munson, Penn., says she tries to avoid spending real money on her Render Ranch farm and her Horse Island and PonyIsland virtual horses, but that she'll spend up to $50 per month in a pinch.

"I don't usually mind spending the money," she says over the sound of real birds chirping in the background. "For me, it's pleasurable to come home and take care of animals that you can turn off and go to bed when you're done with."

In each of the three virtual pets I've created, I've been able to avoid paying a single dime, though the creatures' standing among its digital peers has certainly suffered as a consequence. Compare this to the $600 I paid for my real golden retriever puppy (a steal by most standards), the $50 per month in top-of-the-line dog food she eats, the $100 for spaying, vaccinating and implanting an ID microchip in her skin and the $50 per month or so spent on treats, toys and accessories like fluffy beds. The cost advantage clearly lies with the digital dog.

"Dogs are expensive," my mother warned me before I purchased Dublin. "You sure you don't just want a fish or something?"

Love Stinks

Sherry Turkle is a professor of the social studies of science and technology at the Massachusetts Institute of Technology and the author of the forthcoming book Alone Together: Why We Expect More from Technology and Less from Each Other. She's spent the better part of her career studying the relationships formed when people interact with virtual creatures, computer programs and robots.

Turkle says that while virtual pets like Tamagotchis and Neopets can be a harmless distraction when used in moderation, they have the potential to replace the much more valuable relationships people form with real animals and real people.

"The hook that virtual pets have is that they ask for care," she tells me. "If something asks for care, we're programmed biologically to care for it. When we care for it, we experience it like we've contributed to its consciousness. We are even willing to feel that it cares for us back. There's an expectation of reciprocity that's very deep in our consciousness. [Virtual pets] are socializing us to think that the inanimate is something that is appropriate to attach to, and it raises the question of what kind of relationships we should have with inanimate things."

Turkle goes on to assure that she's "not an alarmist" and that a child who plays with a virtual pet is not necessarily doomed to a life of social ineptitude. She also says, however, that the changes brought on by a society increasingly connected to virtual realities have already taken hold, and that the only way to remedy it is to develop stronger relationships with real living things.

"A real pet has a biology, it knows pain, it attaches to its young, it knows if it's warm or cold, it has a life cycle," Turkle continues. "With a real pet, a child learns responsibility; a child learns to care for another creature. With robots and virtual pets, you turn it off and it's gone. One of my most fascinating findings is that you can make a robot or a virtual pet that's made to measure. For example, you can keep your Aibo [Japanese robot dog] always a puppy. It doesn't have to grow up.

"So what about this notion that we can create companionship that's made to measure? That's not preparing us for life. In a certain sense, the fact that your pet has idiosyncrasies—that it's weird in its own ways, the fact that it gets sick, that you have to take care of it—all these things prepare us for life in the real world, for life with people. A virtual pet does not."

When it comes to idiosyncrasies, my dog Dublin is all stocked up. She pees a little when other dogs scare her, her entire rear end wriggles when she's happy, and she kicks both legs uncontrollably when I scratch her belly. My Tama, iPuppy and FooPet all do cute things too, like retrieve virtual tennis balls and beg for food. But while I admittedly haven't explored the complete programming capabilities of each of my fake pets, I have to doubt that any of their traits, no matter how cute, are unique.

Dublin may puke on the back seat and, since summer started, attract a seemingly incurable amount of fleas. But in a lineup full of a hundred other adorable golden retrievers, I like to think I could find her in an instant. And I know she could find me.

Send a letter to the editor about this story.