| Foot & Mouth Disease: What's All The Fuss About? |
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By Stephen Champion BSc (Hons) BVM&S MRCVS As our rural community of Perthshire will appreciate, we are again faced with the scourge of Foot and Mouth Disease in Scotland. For the first time in over 30 years we may again witness vast pyres, hundreds of yards long, burning into the night throughout Britain. Lines of cattle, feet in the air, silhouetted against the flames that turn livelihoods into ashes. These lines of cattle are breeding lines, nurtured by countless generations of livestock keepers. Your grandfather had scratched his chin at the mart, a nod to the auctioneer, a carefully contemplated addition to the herd - really more than he can afford, but boy she’ll produce some calves. Long nights sitting in the shed waiting for her to calve but a live heifer calf and welcome addition to the herd. The cycle continues and the herd is a little better, a little stronger, a little more productive. But at the end of the day, when the embers are extinguished and the virus is dead, the farmers will be compensated in full, for the value of the meat, the liveweight. So what’s the hassle? I was called to see a dead sheep a while away from the practice. A young hogg and not an uncommon occurrence at this time of year, generally caused by a bout of pneumonia that the vaccine did not manage to catch. The farmer had a concern about FMD although there was no obvious contacts, and I was expecting to see a case of foot rot. Blow me did this sheep not show all the post-mortem signs of Foot and Mouth. (I am probably one of the few young(ish) practitioners who has had the misfortune to have experienced this disease, whilst working in East Africa.) We found none of these very specific signs in any of the others in the flock and MAFF were, quite rightly, of the opinion that if none of the others were infected, it was not Foot and Mouth. I shall always remember this single dead hogg and wonder what was the true cause of its demise, since we are not permitted to send tissues for analysis under the present restrictions. FMD is difficult to diagnose in sheep. This is perhaps why rumour and fear has spread around Scotland even faster than the virus itself, as cases are investigated, signs erected and police called, and farmers, if they are lucky, breath a sigh of relief. Back to the safer, more homely gremlins of BSE, E. coli and Classical Swine Fever. This case is useful to illustrate the enormous infectivity of the disease. A diagnosis is not made because none of the others have it! Why is the disease so awful and so destructive, if the animals concerned usually survive? A question frequently posed by the media and members of the general public. If we assume that the disease causes prolonged loss of productivity, extreme direct and indirect animal welfare concerns and huge economic hardship on the macro and micro scale, then the question that must be asked is how many animals could be infected? The answer is, in theory, the entire National Herds of cattle, sheep and goats, and Flock of sheep. A few facts serve to illustrate the dramatic headline that Foot and Mouth is probably the most contagious disease of man or beast. That is where the fear comes from. A handful of statistics can illustrate this; ones which I have not, I believe, been adequately broadcast on the public media since the outbreak began. The disease is spread by the transmission of virus particles. A pig exhales 400 million of these every day that it is infected, into the atmosphere, to be taken up by the wind and spread 40 miles over land by the wind, and up to 200 miles over the sea. A cow or sheep similarly produces 100 million viruses every day from the blisters that are so characteristic of the disease. So, how many of these viruses does it take to infect another wild or domesticated cloven-hooved animal - the answer is just ten! This means a single pig produces enough viruses in one day to infect 40 million cows, which is an awesome prospect and begs the question, how quickly can we slaughter this pig? It doesn’t unfortunately end there. The virus particles are excreted from every orifice of the poor beast. Once they hit the ground they can survive for up to six months in dung and urine. Furthermore, if animals are not slaughtered, and are allowed to survive the disease, as 95% of them will, they become carrier animals, which can shed the virus into the atmosphere for up to 3 years, infected potentially thousands more animals. Once infected, the incubation period of the present strain (the period from catching the disease to showing signs) is as short as 36 hours. These facts are indeed sobering. This outbreak, beyond our wildest nightmares (or was that BSE?) has fuelled a climate of disbelief, extreme concern and rising panic, tempered only by dispair. The head of the State Veterinary Service informed us on the March 1st, when there were 32 cases in the UK, that he predicted 5 or so new cases a day for a week or two, after which the outbreak should start to subside. At the time of writing we have 95 cases in Britain, 11 of those on Dumfries and Galloway. So, it seems so far he is right, and long may he be so. We are fortunate in Britain to have an extensive and generally effective State Veterinary Service, whose rubber-clad vets, epidemiologists and spokespeople can rush in and with any luck crush the disease like a huge government-funded fire blanket. The wholesale slaughter of thousands of animals is a necessary evil, if ever there was one. Vaccination for FMD as a method of control was abandoned in Europe in 1991, in favour of the current policy. At the time of writing, we have not used vaccination to control the outbreak, nor should we if it can be contained at a relatively low level by current methods. Once we vaccinate, our livestock have antibodies to the disease, our potential European customers will not touch them, and our export market is obliterated for years. The people of Scotland must act collectively to stamp out this threat to our way of life. Vigilance must be maintained as the media loses interest and flirts with fresh stories elsewhere. Support the movement ban as long as it lasts. The Jockey Club has authorised racing to start again. A very bad idea as most National Hunt horses originate from rural areas. We all have to make a living, but patience now will pay off. So stay behind your straw ramps, disinfect boots and cars, throw a stick for the dog in the garden and leave the countryside to those who need to be there. Stay in, put your feet up, and contemplate what all the fuss is about. |
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