ShapeShapeauthorShapechevroncrossShapeShapeShapeGrouphamburgerhomeGroupmagnifyShapeShapeShaperssShape

Lessons on FMD from the front lines

by 5m Editor
26 May 2003, at 12:00am

By Dr Morgan Morrow, NCSU Swine Extension - A British swine pathologist recently summarized for veterinarians in the United States some difficult lessons learned from the devastating foot-and-mouth disease (FMD) outbreak that hit Europe, and particularly England, in early 2001.


Dr Morgan Morrow
Swine Veterinary Specialist

Dr. Stan Done of Veterinary Laboratory Agency, New Haw, Addlestone, Surrey, said the most serious effect of the epidemic has been the economic downturn and resulting stagnation in the British swine industry. He warned members of the American Association of Swine Veterinarians at their annual meeting in Orlando (AASV, Orlando, March 2003, 315-319) that the lessons from the United Kingdom are pertinent everywhere to veterinarians, owners, and government regulators alike.

"No single agricultural sector in the UK is making a profit," he said. Many of the livestock sectors are losing considerable amounts of money, he said. All aspects of the farm-animal side of the veterinary business are similarly affected.

This disease has seen the end of exporting, with consequent loss of export markets. These markets may never be recovered because the waiting time before resumption of exports is allowed is so long that the customer has been forced to shop elsewhere. The direct effect was a 20 percent fall in livestock and dairy output during 2001, which was effectively a cut in GDP of 0.06 percent ($750 million), he said.

As soon as a case is confirmed, movement stops immediately. Right from Day 2, exports were banned. High-value breeding stock could not be exported. Customers developed alternative supplies; and as a result, the UK market, already shrunken by 33 percent over the previous two years, probably will shrink even further, he said.

The failure to export has also reduced the price of finishing pigs. Most of the cheaper cuts for which there is no demand in the UK have not been exported and therefore had to be sold at a loss inside the UK. The cull sow trade also collapsed since the German sausage market was denied, further reducing the viability of the business. Cull sows were often retained and kept beyond their economic point of no return, with consequent low fertility, low birth weight, and litter variability, he continued.

In addition, restrictions necessitated straight-line delivery, causing producers to have to take animals directly to market, with more expense. Cash realization is extremely difficult (sale of breeding stock or sale for slaughter becomes impossible or fraught with tight movement restrictions that require policing), and as a result, stagnation occurs.

Additional health problems further compounded farmers' problems. Dr. Done said that during the outbreak, swine health degenerated as other problems, such as overcrowding and inability to market the animals, swamped the farms, particularly in the affected areas.

The use of medicines and vaccines has probably declined, and the occurrence of PMWS/PDNS increased during these periods of restriction. Labor has been stretched so that welfare standards may have been affected. All forms of surveillance, either passive or active (research projects), have virtually ended over this period, as can be seen from the recent increase in TB reactors as a result of the suspension of tuberculin for about a year (a long time in the evolution of a bacterial disease). Quality assurance inspections also have largely ceased.

Many farmers could not market and had cash-flow problems. Many had to pay extra for veterinary inspections to get long-distance movement licenses or to get veterinary health checks prior to slaughter. Replacement programs have been completely disrupted, to the disadvantage of both the breeding stock supplier and the farmer trying to maintain breeding policy for genetic gain. Those farmers who thought they were at the forefront of things with separate site production, etc., are the ones who are penalized most by the tight movement restrictions.

Dr. Done listed the five main risks to biosecurity:

  1. Importation of meat
    • Legal
    • Illegal
    • By food companies
    • By individual travelers
  2. Livestock movement
  3. Animal-to-animal spread
  4. Extension of the range of disease vectors (new but related species)
  5. Resurgence of disease from a controlled but not eradicated area
In a comment particularly relevant to the situation in the United States and the importance of veterinary vigilance, Dr. Done cautioned, "With our responsibility to safeguard national herds and flocks, we have to know the worldwide distribution of the major hazards (particularly FMD, CSF, and ASF) and the countries that have recently been affected. These are the most likely potential sources of the infection. Even more importantly, we have to know how these fit with the recent trading patterns and tourist-travel patterns because it is the returning idiot with half a sandwich in his back pocket who is now the major potential carrier of the viruses that we need to avoid."

The multi-ethnic nature of many of our societies also has radically increased the wide range of foods that are available and that we are prepared to eat. Demand rises, people want the supply from the original home country, and a trade, legal or illegal, commences. Dr. Done warned, "Biosecurity begins at the outer border of your trading area—not at the country border or state border."

He added, "I can see that in many cases the only border will be the farm gate, which should be kept locked!" Searching the odd plane from Nigeria once every three months is no good when probably every flight has bits of pig, monkey, or any other animal that you care to name, he said. Even in the EU, there is not much warning information at the airport in Sardinia to tell you of the potential hazards of wild boar meat, let alone the hazard from bluetongue.

"We must not forget about global perils," he said. "We certainly had forgotten in the UK, as it had been more than 30 years since the big epidemic of 1967. We also had not kept tabs on the global pandemic of the 0 strain of FMD, which had steadily been taking place since the appearance of that strain in India in 1990."

Dr. Done continued, "We need to have national biosecurity in our mind and on the mind of our clients. Most important of all, (we must) make our governments make our citizens aware and responsible. For instance, why is the beagle sniffing our trouser leg? (We mustn't) let the public think the dog is (looking only for) drugs. (We must) tell them about the hazards and where they are."

He cautioned further that as our demand for meat goes up, and with it the demand for ever more exotic types, so do the possibilities of importing something unforeseen and nasty. The tourist once satisfied by a beach in the sun now wants to visit a jungle in a tropical rainforest and bring back a souvenir, hopefully not a partially cooked piece of meat.

Regarding training programs for veterinarians, Dr. Done said, "We need, as veterinarians, to be trained effectively in infectious and notifiable disease, and we need to be updated at regular intervals. That's because our collective consciousness probably lasts a maximum of 5 years, and we forget what the signs of the disease are. We need to train the new generation of students in this area, not just in caring for cats and dogs and in molecular biology. When you have a national emergency and have to call up the reserves of veterinarians, it would be preferable if they could recognize the diseases."

Not least, he said, it is important to train our own practicing and state veterinarians in epidemiology (this used to be called common sense) and the control of infectious disease (this used to be called animal health and hygiene). If we just concentrate on molecular biology and risk and modeling, we will not have the trained veterinary troops to put in the field against viruses that have fled the field of battle long before they arrive.

The situation is not helped by government perception that there are no longer any risks. This is the reason for the decline in the staffing of the Pirbright Laboratory from about 24 workers in 1980, to 12 in 1986, to only 4 in 2002.

At all times, veterinary practitioners need to be aware of the diseases, where they are, and what the risks are, he said. Together with farmers, they are the front line. In the UK 2001 FMD crisis, in the UK 2000 CSF situation, and in the recent Dutch CSF outbreak, it is likely that signs of all three were missed for at least two weeks. The reasons for this include 1) we probably were not aware of the possibility of outbreak, 2) we had not been retrained to know that the diseases now are perhaps less florid than when some of us trained, and 3) chronic signs in adapted populations are very difficult to pick up without proper clinical examinations.

The 60-year-olds who could remember the last big outbreak were few in number in the large-animal practices of the UK and also in the SVS, he said. Many say that in future there may not be sufficient practitioners to cope with these types of disease. At a recent local meeting in Scotland, one of the senior partners in a practice suggested that perhaps only 32 percent of practitioners in the area worked with large animals.

Dr. Done reminded us that diseases change with time. "Strains adapt; animals may become carriers. We have wild boar now and large feral pig populations as reservoirs. The position has changed and will continue to change, so the process of training has to be continuous."

It is also worth bearing in mind that the average student qualifying today will probably not have studied, let alone have practiced, animal husbandry. This student certainly may never have seen a pig post-mortem and possibly may never have given a pig a clinical examination. How can you expect a new small-animal-trained graduate to be recruited into a containment exercise of something like FMD without knowledge and retraining? You cannot—they need to be trained, and a regular, on-going program has to be developed.

Here are the clinical signs of foot-and-mouth disease in pigs:
  • Sudden lameness
  • Tendency to lie down
  • Lameness
  • May squeal loudly
  • Blisters form on upper edge of the hoof where the skin and horn meet
  • Blisters on the snout or tongue
  • Off feed
  • First clinical sign is fever; animals are reluctant to move, showing some sensitivity in the feet; close examination of the feet will show early lesions; blanching of the coronary skin around the coronary band could easily be missed.
  • About two days later the pigs are lethargic, feverish and lame. They prefer to lie down and when made to move, hobble painfully and squeal loudly, especially when on hard surfaces. Close inspection will show vesicles have formed around the top of the hoof, on the heels, and between the claws. Fluid-filled and some times hemorrhagic vesicles also will be seen on the snout, but foot lesions are most apparent.
On-farm recognition is, of course, now more difficult because of two simple husbandry factors, he said. Firstly, farms are now much bigger, and secondly, they are staffed by many fewer experienced workers who are familiar with, and capable of, recognizing disease signs. You cannot diagnose FMD and other similar diseases away from the pigs and certainly not by computer. The old diagnostic skills are necessary, and the use of a thermometer is absolutely mandatory.

He also said, "The pig industry in the UK has a further complicating factor in that probably 25 to 30 percent of production is outdoors; how easy is it to look for blisters on the nose and feet of an outdoor sow with a litter at foot on a cold day in two feet of mud?"

Regarding the future Dr. Done predicted: "We shall need to have a cadre of trained large-animal specialists, probably on an EU-wide basis, that can be called in to help with a notifiable disease outbreak. We shall then be able to send out trained, experienced vets to second- and third-opinion cases without having to rely on inexperienced vets from other branches of the profession. They will be accustomed to dealing with the science and will keep away from the politics but be able to help both public and agricultural bodies alike. Many of these will also re-invent common sense by becoming epidemiologists—preferably those with Wellington boots rather than a PC. Some others may even understand infectious disease and biosecurity."

It will still be impossible to escape the reality of FMD, he said. You are always playing catch-up because the infectious agent is transmitted before clinical signs develop. In other words, the earliest clinical diagnosis will always be behind the shedding of the virus.

In the future, policing such outbreaks will require local knowledge, Dr. Done said. One of the most obvious features of this recent epidemic was that the regulators did not know what went on in the field, and neither did most field vets. The movement of sheep on and off seasonably available land was carried on in ways that beggars the imagination (7 different farms in 14 days for one set of sheep). Even the collection patterns of cull sows up and down the country was a mystery before the outbreak. The practice of buying and selling through markets without any movement standstill orders is a recipe for disaster, especially when the trading may take place outside the market and may not even be recorded. The disappearance of the local abattoir also makes multi-collection essential for economic reasons, but this greatly increases the chance of the spread of infectious disease.

In the future, he said, it is hoped it will be possible to fully utilize veterinary practitioners in a proper role in the local control of the disease because they will know what goes on. By then, of course, it may be possible to utilize bedside diagnostic kits for both CSF and ASE. We shall also have relearned the problems of restocking after an epidemic. Much advice has been given, but little seems to have been heeded. Already TB seems to have occurred in cattle in new places, and the louping ill virus has appeared in previously free areas as a result of restocking without adequate precautions and investigation of disease status.

To conclude, Dr. Done said, "There is a general lack of understanding about the complexities of FMD, the control of it, and the consequences of failure to do so. Urgency is the word. Total movement restrictions are absolutely essential as soon as you even suspect it. Delaying until the results come in is not good enough because the infection has, if the report turns out to be positive, already been shed. Further, the simple fact is that slaughter after clinical signs emerge allows transmission. Slaughter before the development of clinical signs prevents transmission. The sheer scale of the 2001 FMD outbreak, the biggest and most widespread disease outbreak to hit the UK in the 20th century, even now is difficult to comprehend; and the financial loss still being computed."

One of the great sages of the UK Pig Veterinary Society, David Chennells, remarked that biosecuritv is well-understood by pig farmers: they live with it every day. Dairy farmers have heard of it because of the possibility of BVD infections. However, sheep farmers think biosecurity is a variety of toilet cleaner."

Reproduced Courtsey

Source: North Carolina State University Swine Extension - May 2003