Report of the Departmental Committee on Foot-and-Mouth Disease, 1952-1954.

  • Great Britain. Ministry of Agriculture and Fisheries. Committee on Foot and Mouth Disease.
Date:
[1954]
Catalogue details

Licence: Public Domain Mark

Credit: Report of the Departmental Committee on Foot-and-Mouth Disease, 1952-1954. Source: Wellcome Collection.

    10/166 (page 8)
    THE NATURE* AND INCIDENCE OF FOOT-AND-MOUTH DISEASE I. Foot-and-mouth disease is caused by a filter-passing virus: that is to say an organism so small that it can pass through the minute pores of a filter capable of holding back ordinary bacteria. Animals susceptible to the disease are cattle, sheep, pigs, goats and wild ruminants, and to a much less degree hedgehogs and rats. Laboratory animals such as guinea-pigs, mice and rabbits can be infected artificially with the virus, but are not susceptible to natural infection. Human beings have occasionally been infected, but authenticated cases are rare. The salivation and lameness that are the typical outward symptoms of the disease, and give it its name, are caused by blisters appearing on the tongue and the inside of the mouth and on the feet. Animals that contract the disease do not generally die. Among adult stock the ordinary mortality rate does not seem to be more than 2 to 3 per cent., though it may be much higher if the disease is of ‘a specially virulent type, and it is always high in unweaned stock. The disease usually runs its course in two to three weeks. 2. The seriousness of foot-and-mouth disease lies not in the loss of animals by death but in its interference with productivity, especially by its after-effects on those that recover. In steers, sheep and pigs these are not necessarily grave, though they may sometimes be so, and at the best the animal will suffer a sharp temporary setback. But in dairy cattle they are more likely to be disastrous. The evidence we took in countries where the disease is endemic about the nature and frequency of serious consequences was diverse ; no doubt they vary with such factors as the type of outbreak, the degree to which endemic disease may build up its own resistance, and the extent to which vaccination may mitigate its virulence. But the informa- tion given to us in these countries, and our own observations on farms that had been attacked by the disease, showed that the after-effects included not only loss of condition and of milk-yield, but also abortion, sterility, heart affections, loss of hooves and chronic lameness from secondary infection, and inflammation of the udder, sometimes leading to its permanent impair- ‘ment. Even in countries where the disease is endemic, and some natural resistance has been built up by previous attacks, many cows become totally unproductive. Estimates of the proportion that have to be destroyed for this reason vary. In Italy it is said to be “sometimes 50 per cent.”, but that is exceptional. The average is much lower; in France it is given as 5 per cent. We were told in Belgium that complete recovery from the after- effects is rare and takes a long time. We also obtained from some Continental countries estimates of the financial losses caused by the great epidemic of 1951-52: they are set out in the following Table.t Animal population France ru! Pi .. £45 million... (16 million cattle, 8 million sheep and 7 million pigs). German Federal Republic... £40 million... (11 million cattle, 2 million sheep and 14 million pigs). Belgium YT 7 ... £7million... (2 million cattle, 200,000 sheep and 1 million pigs). Holland eS, a .. £1 million... (3 million cattle, 400,000 sheep and 2 million pigs). These figures, though not exactly comparable, since their basis is not quite the same, represent roughly the direct losses from death, the destruction of * A fuller description is given in Appendix II. + In Great Britain £3 million was paid as compensation for animals slaughtered during the epidemic. The animal population was 9 million cattle, 21 million sheep and 4 million pigs.