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Bovine spongiform encephalopathy

AHVLA investigates all incidents of suspected notifiable disease. If you suspect signs of a notifiable disease, you must immediately notify your local AHVLA Field Services.

What is bovine spongiform encephalopathy?

Bovine spongiform encephalopathy (BSE), commonly known as mad-cow disease, is a fatal, neurological (neurodegenerative) disease in cattle, that causes a spongy degeneration in the brain and spinal cord. The disease is a type of transmissible spongiform encephalopathy (TSE).

The infectious agent is thought to be a protein called a prion. It is believed that in the past animals became infected by eating animal feed containing the infectious agent.

BSE was first diagnosed in the United Kingdom in November 1986 and has since appeared in many other countries including Europe, North America and Japan. Good progress is being made towards its eradication in the UK.

Recent research

It was thought that the BSE agent was a stable, single strain or type but in recent years a small number of cases with different molecular and pathological characteristics have been reported in Europe (including GB), Japan and the USA. The zoonotic potential of these atypical BSE cases is at present unknown.

How to recognise the disease

What to look for

Signs of the disease are not usually seen until the cow is at least four or five years old. Most cattle with BSE show a gradual development of signs over a period of several weeks, or even months, although some can deteriorate very rapidly. Most BSE cases will show at least one of the following signs:

  • change in behaviour
  • apprehension or nervousness (flighty)
  • repeated, exaggerated reactions to touch or sound
  • weakness or high stepping of the legs, particularly the hind legs
  • reluctance to cross concrete or drains/turn corners/enter yards/go through doorways/permit milking
  • aggression towards other cattle and humans
  • manic kicking when milked
  • head held low
  • difficulty in rising, progressing to recumbency;
  • tremors under the skin
  • loss of body condition, weight or milk yield;
  • excessive nose licking

Reducing the risk of disease

The Feed Ban

The BSE Inquiry Report (2000) concluded that the BSE epidemic resulted from the use of infectious meat and bone meal (MBM) in cattle feed. The MBM had been produced by the rendering (industrial cooking) of carcasses of cattle infected with BSE.

It is now illegal to feed potentially infectious material to ruminant animals (mammals that chew the cud such as cattle, sheep, goats, camelids and deer). If there is no other significant route of infection this measure alone will eventually eradicate BSE from UK cattle. It is illegal to:

  • Feed ruminants with all forms of mammalian protein (with specific exceptions)
  • Feed any farmed livestock, including fish and horses, with mammalian meat and bone mealprocessed animal proteins and ruminant gelatine, with exceptions such as milk and eggs used according to the Animal By-Products Regulations.

The restrictions are summarized below:

Feed product

Ruminants

Non-ruminant farmed animals

Permitted animal proteins 
Milk, milk-based products and colostrum, eggs & egg products, gelatine from non-ruminants, hydrolysed proteins derived from non-ruminants or from ruminant hides and skins
Permitted – subject to required sourcing and processing standards under animal by-product controls Permitted – subject to required sourcing and processing standards under animal by-product controls
Prohibited processed animal protein
Includes mammalian meat and bonemeal, meat meal, bone meal, hoof meal, horn meal, greaves, poultry meal, poultry offal meal, feather meal; gelatine from ruminants
Banned (in addition to the restricted proteins listed below, and any animal protein not on the permitted list above) Banned (unprocessed animal by-products are also banned from feeding to farmed animals under animal by-product controls)
Restricted proteins (i.e. restricted to non-ruminant feed use) Fishmeal; blood products; blood meal (only to be fed to farmed fish); Di-calcium phosphate and tri-calcium phosphate (of animal origin only – not mineral) Banned – except that fishmeal is permitted for use in milk replacer powder for unweaned ruminants to be used in liquid form, subject to authorisation, registration and permission requirements. Permitted – subject to authorisation to make feed with these products (see Advice Note 2 of the Guidance notes or registration and permission to use it in complete feed on farms where ruminants are present (see Advice Note 5 of the Guidance notes)

 Further information:

Scientific evidence shows that doses of infected tissue as low as 1 milligram can infect a calf, so there is a need for everyone involved in the feed chain to maintain the very high level of compliance seen to date.

Cattle born or reared in the UK before 1 August 1996 remain excluded from the food chain. At the end of their productive lives, such cattle must be disposed of as fallen cattle (i.e., cattle that die or are killed other than for human consumption), and tested for BSE. Defra has published an information leaflet (PDF) which gives details of the arrangements for the disposal of fallen cattle.

National Feed Audit

To ensure compliance with the law, AHVLA undertakes the risk-based National Feed Audit. This involves taking feed samples for analysis to monitor compliance with BSE-related livestock feed controls in Great Britain.

Catering waste

The feed ban extends to the feeding of catering waste to farmed animals. Catering waste is defined as ‘all waste food, including used cooking oil, originating in restaurants, catering facilities and kitchens, including central kitchens and household kitchens’.

It is illegal to feed farmed animals catering waste that contains or has been in contact with animal by-products as this is a potential source of disease. ‘Farmed animals’ includes any pet animals that belong to a farmed species, such as pet pigs, goats and poultry.

Catering waste includes food waste kitchens, including domestic kitchens, retailers, food factories, distribution warehouses etc. that contains or has been in contact with animal by-products (such as raw eggs, meat, fish products). The ban includes the use of Used Cooking Oils (UCOs) originating in restaurants, catering facilities and kitchens, including central kitchens and household kitchens.

For further information on the disposal of catering waste, see our web pages on animal by-products.

Reducing the impact of disease

Compensation

Compensation is payable for a bovine animal (BSE suspects, offspring and cohorts) compulsorily slaughtered in Great Britain for BSE control purposes. For further information, see the Defra website.

Offspring cull

The law requires the culling of the offspring of female BSE cases, born within two years before, or after, the clinical onset of disease, as soon as possible.

AHVLA traces eligible offspring of female BSE suspects using data from the Cattle Tracing System and farm records. Eligible offspring are placed under movement restriction. If BSE is confirmed in the dam, the offspring are slaughtered. If BSE is not confirmed, the movement restrictions are lifted.

Cohort cull

The law requires that cohorts of new BSE cases are restricted, culled and tested for BSE as soon as possible after they are identified. Cohorts are cattle which were either:

  • born in the same herd as a BSE case, up to a year before or after its birth; or
  • reared with a BSE case when both were up to a year old. Cohort cattle might have consumed the same feed as the BSE case during the first year of their lives.

Movement restrictions on cattle born or reared in the UK before August 1996

All cattle born or reared in the UK before 1 August 1996 are subject to movement restrictions as an extra precaution against meat from these older cattle entering the food chain (milk from such animals can be sold for human consumption).

For further information on movement restrictions on cattle born or reared in the UK before August 1996, see our web pages on registering cattle.

Testing for BSE

EU Member States have been required to undertake active surveillance for BSE in cattle since 2001. The following categories of cattle must be tested for BSE in Great Britain:

  • All cattle which die or are killed other than for human consumption (fallen stock) aged over 48 months
  • All cattle slaughtered normally for human consumption aged over 48 month
  • All emergency slaughter animals or animals found sick at ante mortem inspection aged over 48 months.

All feed cohorts of BSE cases are also tested for BSE.

Exemptions to testing requirements

EU TSE Regulations include a derogation allowing an exemption to BSE testing for cattle in remote areas where there is no carcase collection service, and where the cattle population of the derogated area is less than 10% of the total national cattle population. As a result, cattle keepers in the following areas are exempt from the BSE test requirements:

  • Isle of Wight
    Livestock keepers will be able to dispose of their animals under the arrangements currently in place for other fallen stock. Livestock farmers on the island are expected to make all reasonable efforts to comply with the Animal By-Products Regulations and for the local authority to take appropriate enforcement action against those who make no attempt to comply with animal by-products legislation or who wilfully flout alternative controls set down by the local authority.
    A copy of the letter sent to all cattle keepers on the Isle of Wight is available to download (PDF). While cattle resident on the Isle of Wight born or imported into the UK before 1 August 1996 do not need to be tested for BSE when they die or reach the end of their productive, they must not be sold for human consumption. It remains an offence to consign pre-August 1996 born cattle to a fresh meat abattoir.
  • Scottish BSE testing exempt zones
    The requirement to send bovine fallen stock aged over 48 months for BSE testing applies to all cattle keepers on the Scottish mainland (including those in the designated remote areas defined in the Animal By-Products (Scotland) Regulations 2003 and on the Isles of Bute and Skye). The Scottish Government has published a map of exempt areas (PDF) to show which areas are exempt from the BSE surveillance testing requirements.

While cattle resident within these exempt areas born or imported into the UK before 1 August 1996 do not need to be tested for BSE when they die or reach the end of their productive, they must not be sold for human consumption. It remains an offence to consign pre-August 1996 born cattle to a fresh meat abattoir.

Testing your cattle: approved test premises

Premises approved to undertake TSE testing of fallen cattle are listed in the document TSE Approved Plants (PDF).

Livestock keepers should contact the TSE Surveillance Helpline on 0800 525 890. The Rural Payments Agency operates a voluntary survey for fallen stock sheep aged over 18 months. Producers may call the TSE Helpline on 0800 525 890 if they wish to offer a sheep for the survey. Carcases which are accepted will be collected and disposed of free of charge

For further information, see our web pages on fallen stock.

Becoming an approved test facility

Any site meeting certain animal health legislative requirements can apply to be approved to undertake BSE testing work.

Legislation

Further information

Page last modified: 2 January 2013