MAD DOGS AND ENGLISHMEN

Science: Britain's quarantine laws are almost 100 years old. With advances in vaccinations and disappearing borders, shouldn't we find a kinder alternative? Hilary Bower reports

QUARANTINE RAISES hackles - and not just those of the dogs and cats which endure six months of it to come into the country. Pet owners and our government have been at loggerheads for most of the past decade over whether, in this age of vaccines and disappearing border controls, quarantine is needed.

Britain is one of the few countries that still bases its defence against rabies on isolation. Campaigners have long argued that vaccinations, blood tests and pet passports offer at least the same level of safety as quarantine. But the Conservative government persistently refused to accept this, despite a unanimous recommendation for change from the Commons Agriculture Committee in 1995. Now Labour has sent yet another pack of experts to investigate.

Rabies is not a nice disease. A bite from an infected animal transmits the virus into the central nervous system. In some cases it acts immediately, causing fever, spasms, delirium and its most distressing symptom, hydrophobia: the sight of water can provoke the convulsions which eventually kill. In other cases, the virus inexplicably goes to sleep, waking to cause an agonising death up to 20 years later. Unless anti-rabies treatment is started within a few days of the bite, the virus, it has long been thought, is always fatal. It is new doubt about this belief that is at the root of scientific concerns about quarantine. Under the current system, pets entering Britain from any country (rabies-free or not) must spend six months in kennels, on the basis that any with rabies will be discovered and the pet will be destroyed before becoming a threat to humans or other animals.

Anti-quarantine campaigners say this is not only antiquated, but leaks like a sieve. Even the most law-abiding find ways to evade quarantine. Estimates from the Quarantine Abolition Fighting Fund (Quaff) suggest up to 100 animals are smuggled into Britain a week. Quaff wants a system based on vaccination, which it says is effective the world over.

This involves tattooing or microchipping pets to prove identity, immunisation with inactivated vaccine, then blood-testing to ensure there are sufficient positive antibodies against rabies four months later. The results are recorded in a "passport" by an officially designated laboratory. Almost all countries in Europe use a similar system and there have been no recorded cases of rabies in vaccinated dogs in Europe for 15 years, and only three cases in cats.

In 1994, Sweden abandoned the quarantine it had maintained since last century in favour of this practice and although the number of animals entering the country has leapt from 1,000 to around 30,000 per year, there have been no cases of rabies.

Indeed, Britain's Ministry of Agriculture, Food and Fisheries appears to have accepted the principle of control through vaccination. In 1994, it implemented the EU's Balai Directive to allow dogs and cats to be traded commercially between EU member states without having to go through quarantine. Dogs and cats can be moved without restriction as long as they have lived on a registered holding with no contact with wild animals since birth, have been identified by an implanted microchip, vaccinated at least six months before export and achieved the required level of antibodies at blood test.

"We don't need a solution that treats New Zealand, where there has never been a case of rabies, and Sweden, where there hasn't been a case since 1870, in the same way as India and Nigeria which have cases all the time," says Dr Jack Done, head of pathology at the MAFF central veterinary laboratory until 1984 and now a key proponent of change. "But if you want a belt- and-braces solution for animals from rabies-free countries, you could say they've got to be vaccinated and then tested to show the vaccine has taken. You could even say you want to keep quarantine, but instead of doing it in kennels, you do it in your own home."

But it is not only travellers from rabies-free countries that don't need quarantining, say campaigners. The vast majority of Europe poses no threat because where rabies exists, it is largely fox-mediated.

Proponents of quarantine argue an outbreak of fox rabies would be hard to combat and more dangerous to humans in Britain, due to large numbers of urban foxes and the difficulty of getting them to take poisoned baits because of abundant food. But such an outbreak is unlikely. Though fox- and dog- mediated rabies are similar strains, fox rabies is less infectious in dogs and vice versa. There is no recorded incidence of a dog with fox rabies infecting another dog or other animal. So a dog infected with fox rabies is an end host. Of course, it could still bite a human, but it would not trigger the scenario most feared - the return of rabies.

Also, outbreaks of fox rabies in Western Europe have been steadily reducing. Belgium, Germany, Austria, Switzerland, Luxembourg and Italy all have stringent eradication programmes, and last year France was on the verge of being pronounced rabies free when a French dog was bitten by a rabid German fox on the border - quite how it was confirmed to be German is not known. Veterinary experts calculate that, given the current incidence of fox rabies in France, if 5,000 dogs entered the UK from there a year, only one every 250 years is likely to arrive incubating rabies. Dog rabies is a different story: it passes easily from dog to dog - and causes 35,000 deaths of humans worldwide. But it is found almost exclusively in Asia, Africa, Central and South America with Turkey the closest pool to Europe. Though Quaff says immunisation would render animals from these countries no threat, they are prepared to limit their demand for change to just rabies-free and fox-rabies-controlled countries.

Some scientists believe there are still concerns about how foolproof vaccination is. The most important fear is that antibodies to rabies have been found in dogs which have never been in contact either with rabies virus or the vaccine. This flies in the face of accepted wisdom that rabies is invariably fatal, and casts doubt on the ability of blood tests to prove immunity. According to Dr Gordon Scott, Reader Emeritus at the University of Edinburgh's Department of Tropical Animal Health, studies in countries where rabies exists repeatedly find around 30 per cent of wildlife carry antibodies to the virus, which means they must have been exposed to rabies and survived. Antibodies have also been found in hunters in Germany. "In other words, the detection of antibodies in the serum of animals which have been vaccinated does not necessarily mean it is due to the vaccine," says Dr Scott.

More seriously, studies have discovered healthy unvaccinated dogs with antibodies to rabies which also intermittently secrete large amounts of active rabies virus. This means they are carriers, but under the proposed vaccination scheme they would be mistakenly identified as rabies-protected, because their blood would show the antibodies linked to vaccination; in reality they are as infectious as any rabid dog. Imagine you live in Texas - where there have been recent outbreaks of dog rabies. As a good pet owner, you follow procedures by vaccinating your dog and blood-checking its immunity. With your pet in possession of its passport, you both return to the now-unquarantined UK. It is possible, say vaccine sceptics, that your pet is carrying rabies.

There are some relatively simple tactical ways around this. A vaccine could be tagged with a biochemical marker that would differentiate the antibodies it produced from any already in the blood. And animals should be blood-tested before and after vaccination. "If the first sample has no antibodies and the second has, there is no reason why you shouldn't let the animal in. If the first serum sample has antibodies, you're in trouble. That dog could be a carrier. We don't know how to identify carriers definitely, especially since they do not appear to secrete virus all the time. What are you going to do? Destroy all dogs with prior antibodies?" asks Scott.

The prospect of healthy rabies carriers is a nasty one, not only for other dogs, but humans too, who might be infected via a licked cut or scratch.

These scenarios are likely to concern a tiny proportion of animals, particularly if they live in Europe. The problem, says Gordon Scott, is that we don't know what proportion. "The vaccination- certification approach has not been proven yet. Everyone is still working on the law of the 1950s which says you do not get asymptomatic infections - if something is infected with rabies, it dies."

Scott says before any change is made we need to know for sure the prevalence of antibodies in humans and dogs in Europe and the percentage of animals and humans unknowingly surviving rabies. Work by US investigators in Nigeria, where rabies is endemic, suggests around a third of humans have been infected with rabies, but not developed the disease. "There's about 10 years' research there. From the point of view of human beings the risks involved in changing the system are very low. But if you are infected, it is horrific. Dare I say, the companion animal trade is a luxury..."

According to Jack Done, the risk of a dog being an asymptomatic carrier is 10 to the minus 90. "British people have been brainwashed to believe that no risk is the only acceptable risk. There's no such thing. Until rabies has been wiped out, there is always a risk, but you're dealing with tiny figures."

Most Britons are at more risk from rabies as a result of their own behaviour, he adds. "How many people go on holiday to countries where rabies is endemic without being vaccinated? About a quarter. So here we are believing we must keep out rabies, yet we go into countries like Kenya or Turkey where the risk of a bite from a stray dog is much higher than any chance of being infected by a vaccinated, blood-tested animal in Britain."

Then there's the fact that quarantine is far from 100 per cent safe. The gaping hole in it is evasion. Though estimates range from the government's 100 illegal entries a year to Quaff's 100 a week, the bottom line is that numbers are growing. Pet owners who rely on vaccines to protect their dogs elsewhere have become increasingly militant.

Also, the six-month duration of quarantine is based on the best guesstimate of how long the majority of animals take to show rabies. Between 1922 and 1970, says Jack Done, three out of the 27 dogs that succumbed to rabies did so after their six months, giving quarantine a failure rate of 11 per cent. To cut this to five per cent, quarantine would have to be extended to nine months, for one per cent, dogs should be in isolation for 15 months.

Since 1970, there have been no proven cases of rabies in quarantine - a situation hard to attribute to anything other than pet owners vaccinating pets while living abroad (common among ex-pats).

"We have six months' quarantine as it is a politically convenient compromise," says Done. "If we had no quarantine from 1970 until now, we would still have had the same number of cases. Zero."

Critics of change say removing quarantine will increase the number of animal movements, and therefore the risk. If Britain were to have the same rise as Sweden, then animals entering the country annually would grow from around 5,000 to 175,000. And, they say, policing a vaccination- certification system would be a logistical nightmare: microchips can move about the body, not all detectors detect all chips and certification can be forged.

There's no doubt that more moving animals means more risk, says Done. "But one case of rabies is not a disaster. What chance did the two dogs which have died of rabies outside quarantine in the last 30 years have of producing an epidemic? The answer is - not a cat in hell's chance."

Critics say vaccination will cost taxpayers more money in the form of inspectors, checkpoints and increased use of anti-rabies jabs in uncertain cases, while quarantine is entirely funded by pet owners. In 1994, France spent pounds 3.2 million on anti- rabies treatment. But a survey from the Centre for Agricultural Strategy has found pet owners willing to pay up to pounds 4,000 to keep their mutts by their sides. The government could easily ask for an import fee of double, treble or even quadruple the approximate pounds 200 the vaccine procedure will cost. (On average, quarantine costs pounds 1,500.)

According to Martyn Edelsten, a senior lecturer in tropical animal health in Edinburgh, the problem of change is uncertainty. "Say you are bitten by a dog here which has been overseas. The owner says no need to worry, it's been vaccinated, here's the certificate. But nothing is 100 per cent. Do you start a course of anti-rabies vaccine? What will doctors say - 'look the dog's vaccinated, it's pretty well certain its alright'. Pretty well certain? I'd want 100 per cent certainty. You will get a lot more anti-rabies vaccine used because nobody is quite sure."

There never was 100 per cent certainty though - we just thought there was and felt safe.

QUARANTINE IN THE DOCK

QUARANTINE has been in place in Britain since 1901; the combination of strict controls and muzzling of dogs eradicated rabies here by 1903. The two outbreaks since - one in 1918, traced to soldiers bringing home dogs they had befriended - were swiftly contained.

Anti-quarantine campaigners argue that Britain's laws breach not just scientific sense but European law, and they are about to air their views in the High Court. Their case centres on an EU national's microchipped, vaccinated and blood-tested cat refused entry here without quarantine. It rests on Article 30 of the Treaty of Rome, under which both owner and pet (classed as goods under EU law) have the right to free movement in member states.

Britain's special dispensation to Article 30 (for the sake of rabies control) now depends on quarantine being proved essential to the protection of British health. If the same level of safety can be achieved by less onerous means, the dispensation will no longer apply.

If the case is successful, it will signal the start of many European holidays for suitably passported pets.