The slogan “A dog is for life, not just for Christmas” created by the Dogs Trust, a leading UK canine charity, has moved a stage nearer reality, now that a South Korean biotechnology firm has successfully cloned a beloved American pit bull terrier.

Before his death, Ms McKinney's brave former companion called Booger fought off a crazed mastiff which unexpectedly attacked her. She then had to undergo months of painful hospital treatment, but Booger also helped her through the long period of recovery, learning to fetch and carry items around the home. Ms. McKinney never forgot her loyal companion, who died back in 2006. She had cells from his ears frozen, in the hope that one day, he could be cloned.

It meant that she had to sell her home in California to meet the cost, which is said to have been at least US $50,000, when the opportunity became available thanks to RNL Bio, a company set up by scientists based at Seoul National University. Bernann McKinney was finally rewarded by the birth of five puppies, all carrying Booger's DNA, in August 2008. The company itself is now offering its cloning service on a worldwide basis, and estimates it could clone up to 300 dogs each year.

Opinion on the use of this technology is currently sharply divided, but over time, it could mean a radical shift in the way in which dogs and cats are obtained. Cloning might help to overcome excessive breeding, and reduce the numbers of unwanted pets. There is even the possibility that within a decade or two, pet stores might be collaborating in arranging cloning of beloved pets on behalf of their customers.

Ethical and welfare concerns

At present however, the price of the procedure if nothing else is largely prohibitive, but this is likely to fall, particularly once the techniques and technology become more reliable and widely-available. There are a number of ethical issues and welfare concerns surrounding cloning however, which will not be so easily overcome. The first successful cloning of a dog, which resulted in the birth of an Afghan hound called Snuppy in 2005, also in South Korea, saw over 1000 embryos having to be transferred into 123 bitches. Out of all these, just three pregnancies occurred, with one ending in a miscarriage and another puppy dying soon after birth. There are also fears that clones may not be as healthy as other puppies over the longer term. It presently remains more straightforward to clone cats rather than dogs, thanks to key differences in their reproductive cycles. This was illustrated by the case of Genetic Savings and Clone, a California-based enterprise. Although the company was able to produce cats by cloning them, it encountered much greater difficulties with dogs, and is no longer in business. Cats are induced ovulators, which means they produce eggs in response to mating, making it relatively easy to trigger their reproductive cycle artificially. Dogs, however, only come into season once or twice a year.

Not an exact match

Some owners may also be disappointed by the results, if they believe that they will receive an exact replica of their original pet through cloning. As far as dogs and cats with patterned coats are concerned, clones are unlikely to replicate the markings of their ancestor exactly. Then there is the issue of temperament, as this is not something which can be guaranteed either, being affected in part by the environment in which the pet is kept.

The implications of cloning also extend beyond individual pets, into the show field. The American Kennel Club (AKC) is keeping the matter under review. There may ultimately come a stage when, as currently occurs in horse racing, DNA from both parents is required to compare with that of their offspring, to prevent clones slipping through the registration process. Security issues surrounding leading champions will also become a key issue. They could otherwise be cloned and then mated with other dogs.

On the other hand, cloning might be used in a positive way to assist the survival of rare breeds. In the UK for example, a number of breeds such as the Sealyham terrier have been identified as being at risk of dying out. Should the DNA of these dogs be stored now, for potential cloning in the future? There could also be the possibility of identifying and breeding out potential weaknesses such as hip dysplasia too. This would run contrary to the Kennel Club's stated policy however, with the organisation presently being opposed to the procedure.

Wherever you stand on the issue of cloning therefore, it will inevitably have a far-reaching and significant impact as far as pets are concerned. The debate has barely started!