Scientists in South Korea have produced the first dog clones, they report in Nature magazine this week.
One of the puppies died soon after birth but the other, an Afghan hound named Snuppy, is still doing well after 16 weeks, the researchers say.
Snuppy joins a host of other cloned animals including Dolly the sheep, CC the cat and Ralph the rat.
Scientists hope dog clones will help them understand and treat a range of serious human diseases.
"The dog has characteristics similar to human beings," lead researcher Hwang Woo-suk of Seoul National University, South Korea, told the BBC. "Some of their diseases are almost the same as human diseases.
"So [dog clones] could be very valuable in finding technologies useful for curing human diseases. This is our main research call."
Snuppy, whose name stands for Seoul National University puppy, was made from a cell taken from the ear of a three-year-old male Afghan hound.
Scientists took the genetic material from the ear cell and placed it into an empty egg cell. This egg was then stimulated to start dividing and develop into an embryo.
Once growing, it was transferred to Snuppy's surrogate mother, a yellow labrador. The Afghan pup was born by caesarean section after a full 60 days of pregnancy.
Although many other animals have been successfully cloned, dogs are notoriously difficult: the South Korean team only obtained three pregnancies from more than 1,000 embryo transfers into 123 recipients.
Cloning dogs is notoriously difficult
Of these, one miscarried and one died soon after birth; only Snuppy remains.
The hairy puppy, like other cloned animals, is generating a flurry of interest around the world.
Some people are concerned about the ethical implications of this research.
"Canine cloning runs contrary to the Kennel Club's objective 'To promote in every way the general improvement of dogs'," Phil Buckley, spokesman for the Kennel Club told the BBC News website. "Cloning cannot be used to make improvements because the technique simply produces genetic replicas of existing dogs.
"Also, will these cloned dogs end up being used in the laboratory? That opens a whole new can of worms."
Dr Freda Scott-Park, President Elect of the British Veterinary Association, is concerned about the likely reaction of dog lovers.
"This report demonstrates just how fast the world of genetic manipulation is moving and no one should underestimate the far-reaching consequences of this work," she said.
"Sadly however, the media interest is likely to attract pet owners keen to re-create their much loved pets.
"No one can deny that techniques that advance our understanding of diseases and their therapy are to be encouraged. But cloning of animals raises many ethical and moral issues that have still to be properly debated within the profession."
However, another member of the cloning team, Dr Gerald Schatten from the University of Pittsburgh School of Medicine, US, said they are not in the business of cloning pets.
"The overall objective of this programme is to learn about the root causes of diseases," he told the BBC. "We believe it is possible, if you can responsibly develop the ability to derive stem cells from cloned dog embryos, that our very best friends may turn out to be the first beneficiaries of stem cell medicine.
"And as we treat naturally occurring diseases in dogs, we'll learn about whether it is effective in our pets and we'll also learn whether it's safe and effective for our loved ones."