An Afghan hound born in South Korea in June adds dogs to the small list of animal species that have been successfully cloned (see Dogs cloned from adult somatic cells ). The birth marks another first for the Korean-based group that cloned the first human embryos last year.

The development has some scientific significance, on account of the emerging importance of the dog as a model for the study of certain aspects of human genetics, development, behaviour and disease.

A dog genome project is being undertaken by a US team, and the cloning of dogs could provide an additional tool for researchers. The number of cloned dogs that will be needed for such research is probably small, however. Scientists such as Elaine Ostrander of the US National Human Genome Research Institute, head of the dog-genome project, do most of their work with pets living at home, not with kennels of animals bred for research. So the ability to clone dogs is unlikely to have more than a marginal impact on how such research is done.

It is unlikely that even the most obsessive pet owner would contemplate preparing more than 100 failed pregnancies for just one successful birth.

Cohorts of cloned dogs could potentially be used to study the respective influence of genes and environment on particular traits, however. And if it were possible to derive embryonic stem-cell lines from cloned dog embryos — something that's so far only been done in mice and humans — then canine diseases could be studied more easily in Petri dishes, perhaps providing insights into disease mechanisms and even identifying new therapies. Deriving embryonic stem cells would also pave the way to therapeutic cloning in dogs — perhaps providing a useful animal model for research into human health.

The initial dog-cloning experiment has proven the process to be remarkably inefficient, however, with only two live births — and one survivor — from a total of 1,095 embryos implanted in 123 surrogate mothers. This offers scant prospects for commercial pet cloning, the application of the work that the media is likely to make a fuss about. It is unlikely that even the most obsessive pet owner would contemplate preparing more than 100 failed pregnancies for just one successful birth — especially when there is no guarantee that the cloned dog will behave like the one they hope to duplicate. In such circumstances, the cloning of dogs for pet owners remains ethically indefensible.

The Korean researchers named their new dog Snuppy, for Seoul National University puppy (one can almost imagine the name being chosen — presumably on a conference call with the university press office). Let us wish him a long and happy life and hope that now that the concept behind the birth is proven, dogs are cloned only when strictly required for research purposes, and that effort is concentrated on work that carries the most likely rewards for canine and human health.