Nancy Rothwell

Three million animals are used in experiments each year - a necessity to prevent disease in humans and animals.

Over the summer I have become infuriated by friends and colleagues outside the university sector, taxi drivers and the local shopkeeper who comment on how good it is to be on the "long summer vacation". I've given up attempts to disabuse them of the idea that academics take to the hills for two months of R and R, but instead snatch a week or two's holiday in between research projects, writing grants, preparing for new classes and catching up on vast amounts of paperwork.

But university "dons" don't do too badly in the opinion polls of "respected professions" or people who are "trusted", although inevitably they come below doctors - who make people better, or at least try to.

Interestingly it is often vets who come at, or close to, the top. Vets are the frequent subject of affectionate TV programmes. They deal with customers who don't argue (but may sometimes bite) and, based on the excessive bills for our beloved dog, they can't be too badly off (like many pet owners, I will question a bill from my dentist, but happily sign a large cheque for the vet's fee).

I wonder if their popularity prevails in other countries? Britain has long been a nation of animal lovers, and many of us have pets that we dote on.

My colleagues from abroad are somewhat bemused to hear that annual donations to the Royal Society for the Prevention of Cruelty to Animals normally exceed those to National Society for the Prevention of Cruelty to Children. Though, interestingly, we are also a nation with quite high meat consumption, so our passions are a little selective, perhaps because we forget about the origins of our bacon sandwich.

This love of animals is often cited as the reason for significant opposition to the use of animals in biomedical research - particularly where this involves companion animals (the concern expressed about using cats and dogs often exceeds that for primates). The debate over animal experiments and the actions of animal rights groups have featured heavily in the press in recent weeks, with more than 250 articles in the second half of July alone. These have focused mainly on the actions of relatively small groups of extremists who have "targeted" individuals and their families.

But, in fact, several MORI polls suggest that most of the population (more than 90 per cent) is willing to accept the use of animals, with important caveats about regulations to minimise suffering and restrict such experiments to cases where no alternative can be identified. Yet it seems that some of those who oppose animal experiments feel so strongly about it that they are willing to use extremely threatening and violent means.

Here, then, is a dilemma. First, almost all of the medicines, vaccines and surgical techniques used for our beloved pets have been developed through research on animals. The case to support experiments on animals is made mostly on the basis of medical advances for humans but, as a nation of animal lovers, it is probably also relevant to consider whether experiments on some animals are justified to improve the lives of many others. Some will inevitably say "no", on ethical grounds, but I wonder how many pet owners would deny veterinary treatments for their pets (let alone for themselves or their children) that had been developed in animals?

Another dilemma arises from the actions of our pets. Nearly 3 million animals are used in experiments under Home Office licences in the UK each year - most will simply be killed humanely, but we cannot deny that some will experience suffering or pain, although considerable measures are taken to minimise this. This number is tiny compared with those we produce for food, and is also very small compared with another figure of suffering. A couple of years ago, the British Mammals Society reported that more than 200 million animals were killed each year - many tortured and left to die - by domestic cats (most of them pets).

I am certainly not advocating a major cull of domestic cats. Indeed, this slaughter can be limited effectively by giving Tiddles a loud bell or by taking simple measures to curb his nocturnal activities. But it is interesting to see the balance of numbers against those used in animal experiments.

We go to great lengths to ensure that our pets are happy and healthy (and I'll stand up and be counted along with all the sentimental pet owners) - and a good vet would get my popularity vote. But there is extensive evidence of the enormous benefits in diagnosis, treatment and prevention of major diseases in humans and animals that have resulted from experiments on animals. We now face the danger that future benefits will be curtailed and the research will transfer overseas.

Nancy Rothwell is MRC research professor in the faculty of life sciences at Manchester University.