BSE: Disease control & eradication
BSE was first diagnosed in November 1986 at the Central Veterinary Laboratory, Weybridge. The two cows concerned came from herds in different parts of England, but showed the same abnormal neurological symptoms.
The epidemic reached its peak in 1992. Since then the number of cases has decreased. There are now fewer than 4 suspected clinical BSE cases restricted per week in Great Britain, compared to more than 850 per week in 1992.
The average incubation period of BSE is five years, and only very rarely indeed do animals under three years of age display symptoms. This suggests that cattle in Great Britain first became infected in the early 1980s.
There are a number of theories on the origin of BSE, but the means of spread of BSE in the national cattle herd which created the epidemic was by contaminated animal feed.
Government measures to eradicate BSE
The Government has introduced a number of measures to protect animal health and, in time, to eradicate BSE.
The key animal health control measure is the feed ban which was introduced in July 1988. This was brought in to prevent the incorporation of potentially infectious material into feed for ruminants, and so prevent cattle which were not already infected from becoming infected (see Feed Ban page for details of the further controls on feed introduced in the UK in 1996, and the EU-wide measures which applied from 2001). If there is no other significant route of infection this measure alone will eventually eradicate BSE from UK cattle.
Further Government action
The measures taken by the UK Government, in particular the feed ban, have already resulted in a sharp decline in the incidence of BSE. If no additional action were taken the incidence of BSE would continue to decline until it was eradicated. However, the Government has always aimed to accelerate this process by slaughtering animals which have most risk of developing BSE. One of the preconditions of the Florence Framework was the selective slaughter of animals considered to be at a higher risk of developing BSE.
The UK Government announced on 16 December 1996 that the selective cull would go ahead early in 1997. The programme targeted animals which, in the opinion of an officer of the State Veterinary Service, might have been exposed to infection in feed.
Under the offspring cull, the UK culls the offspring of female BSE cases born within two years prior to, or any time after, the clinical onset of disease.
Under the cohort cull, the UK also culls the cohorts of BSE cases.
Page last modified:
6 August, 2007