A group of scientists from Seoul National University on Wednesday unveiled their furry creation, a black and white Afghan hound named Snuppy that is genetically identical to its three-year-old "father".
But while geneticists hailed the breakthough as a step towards beating human diseases that have so far eluded medical science, others called for a worldwide ban on human cloning, saying that the pup had brought that eventuality nearer.
The achievement of the team led by Professor Hwang Woo-Suk is considered so significant because many canine diseases such as diabetes, cancer, dementia and problems in heart muscles, hips and joints are similar to those in humans.
Professor Kong Il-Keun, a cloning expert at Suncheon National University, said cloning dogs had immense clinical value because canines have 203 genes that can be used for studying human diseases while the pig has only 65.
King Chow, assistant professor of biotechnology at the Hong Kong University of Science and Technology welcomed the latest advance, but warned that the scientific community needed to be on guard against possible human cloning.
Hwang says cloning humans is
"The development of the technology is a good thing in itself; but how we monitor it and who we allow to use it will be of great importance," he said.
"If it has been done to help research and understanding of how humans developed from a single cell - an area in which there are huge holes in our understanding - then this is a very important development.
"But it if is to be taken further and applied simply to make multiple clones - then I have strong objections."
In order to create Snuppy - short for Seoul National University Puppy - the team had to create 1095 canine embryos that were transferred into 123 surrogate bitches resulting in three successful pregnancies.
One foetus miscarried, but two others were delivered, including Snuppy on 24 April. The other cloned dog died after 22 days from pneumonia.
Scientists have already cloned a
sheep, pig and other animals
Gerald Schatten of the University of Pittsburgh School of Medicine, Hwang's research planning and technology adviser, said the poor success rate justified a ban on human cloning.
"Because this again shows that reproductive cloning is unsafe and inefficient; we call for a worldwide ban on human reproductive cloning, which is also unethical," said Schatten.
Since scientists first cloned a sheep named Dolly in 1997,
researchers have gone on to clone mice, cats, goats, pigs, mules, horses and deer.
But of all mammals, the cloning of dogs is technically the most challenging because of the difficulty of acquiring mature eggs.
Some experts say the cloning of a dog demonstrates that most of the key techniques needed to clone humans are now available.
"Cloning technologies are developing very fast and I am afraid that primates and humans will be next"
Professor at University of Ulsan
"Bring me human eggs, the necessary social consensus and legal permission and I can get you your replica within a year," said Park Se-Pill, a senior researcher of Maria Biotech and a top cloning expert.
"In contrast to widespread public belief, cloning a human is much easier than cloning a cow or a pig," Park told AFP.
Hwang made international headlines in February 2004 when he announced the first-ever cloning of human embryos, from which his team harvested "therapeutic" embryonic stem cells.
But he said in June that the cloning of human beings would remain an impossible and dangerous fantasy for decades to come, and that it was "not only ethically outrageous and medically dangerous, but technically impossible."
In an apparent effort to calm concerns that his team would now work towards creating a human clone by first working on primates, he said on Wednesday that he had given up attempts to clone monkeys as being technically too difficult.
But Park of Maria Biotech said Hwang was downplaying the possibility of human reproductive cloning to avoid getting entangled in a controversial ethical debate.
University of Ulsan Professor Koo Young-Mo said there was a danger of the latest findings falling into the wrong hands.
"What if rogue scientists use the cloning technology that has now been publicised to make human replicas?" said Koo, who teaches medical ethics.
"Cloning technologies are developing very fast and I am afraid that primates and humans will be next."