Scrapie: how to spot and report the disease

Scrapie is a fatal brain disease of sheep and goats. There are many clinical symptoms of the disease such as irritation, changes in behaviour and changes in posture. These clinical signs can be confused with other sheep diseases. It is not known to pose a risk to human health.

Clinical signs

There is often a general change in temperament or behaviour weeks before more specific signs develop, although in some cases an affected animal's condition may worsen rapidly or it may be found dead. Animals with scrapie show a combination of the following signs, although skin irritation may be less evident in atypical scrapie. None of these signs are a definite indication of scrapie.

Changes in behaviour

• becoming excitable
• drooping ears
• increased nervousness or fear response
• lagging behind
• aggression
• depression or vacant stare

Skin irritation

• repeated rubbing of the head and body against objects such as fences, posts or hay racks
• repeated scratching of the flanks. Horned animals may scratch with their horns
• nibbling or grinding teeth when rubbing themselves or when rubbed firmly on the back
• continued scratching of the shoulder or ear with a hind foot. Unusual or agitated nibbling of the feet, legs or other parts of the body
• excessive wool loss or damage to the skin

Changes in posture and movement

• trembling (mainly of the head)
• unusual high stepping trot in early stages
• severe inco-ordination
• stumbling
• standing awkwardly
• weak hind leg
• unable to stand

Later clinical signs

• weight loss
• death

Preventing and controlling scrapie

Cleaning and disinfecting

The classical scrapie agent can remain in the environment for several years.

However, it’s resistant to most commercial disinfectants and thorough cleaning and disinfection of buildings will still reduce the level of infection.

You must disinfect buildings and equipment according to Environment Agency requirements, if you’re in England or Wales.

If you’re in Scotland, you must follow Scottish Environmental Protection Agency requirements.

Breeding for resistance

Some sheep are more genetically resistant to classical scrapie than others. But there appears to be no genetic resistance to classicial scrapie in goats.

You can use genotype testing to identify scrapie resistant sheep and then try to breed animals that are more resistant.

Talk to your vet to find out more about how to do this.

Buying resistant animals

You can make sure any animals you buy are either:

• genetically resistant to classical scrapie
• from flocks or herds which have been monitored for at least three years and are found to be free of classical scrapie

Milk and colostrum

Classical scrapie can be spread through colostrum and milk.

You should make sure any replacement colostrum or milk you buy comes from flocks or herds which have been monitored for at least three years and are found to be free of classical scrapie.

Don’t use pooled colostrum or milk in intensively managed flocks or herds of animals that are genetically susceptible to classical scrapie - use cow colostrum or artificial milk replacers instead.

Lambing or kidding

Sheep and goats can be infected by classical scrapie if they come into contact with birth fluids or afterbirth from infected animals.

You should remove afterbirths as soon as possible - you should also regularly clean and disinfect buildings you use for lambing or kidding.

Human health implications

It is not known to pose a risk to human health.

Legislation

An outbreak will be controlled in line with the contingency framework for exotic notifiable animal diseases.

What Animal Health will do

After receiving a report of a suspected scrapie case, a Veterinary Officer (VO) from Animal & Plant Health Agency (APHA) will visit and examine the animal as soon as possible. The subsequent action depends upon the outcome of the VO's examination.

Negative scrapie diagnosis

If the VO decides that your animal is not a scrapie suspect, they will not restrict its movement. You should then contact your private veterinary surgeon to discuss an alternative diagnosis or treatment. If you retain the animal and remain concerned that it is affected with scrapie because of further developments in clinical signs, you must again report your suspicions to APHA.

Sometimes, when the VO does not suspect scrapie, they may advise you that your animal requires killing on welfare grounds because it is suffering from another disease. You will not be paid compensation for the animal. You must comply with the requirements for disposal of fallen stock.

Animals placed under observation

In some cases the VO may decide that it is necessary to keep your animal under observation, to determine whether or not it is a scrapie suspect. If so, they will restrict the movement of all the sheep and goats from the farm. The VO will periodically visit the animal during the observation period. You remain responsible for the welfare of the animal. If at any time the VO is able to rule out scrapie, they will lift the movement restrictions.

If APHA suspects that your animal was affected with scrapie, they will take control of its carcase. APHA will arrange scrapie testing and disposal of the carcase. If APHA does not suspect that your animal was affected with scrapie they will lift the movement restrictions. You must comply with the requirements for disposal of fallen stock.

Scrapie suspected

If the VO decides that your animal is a scrapie suspect, they will issue a notice of intention to kill the suspect and they will restrict the movement of all the sheep and goats on the farm.

Following the issue of a notice of intention to kill, the VO will determine the compensation payable. The VO may arrange for the scrapie suspect to be transported to the VLA where it will be killed as soon as possible and tested for TSE. The VLA collects samples for vital research. In some cases, the VO will kill the scrapie suspect on the farm. APHA will then arrange for the collection, testing for scrapie and BSE, and disposal of the carcase.

Scrapie confirmed

Scrapie may be confirmed after death in a scrapie suspect or through the TSE testing programme described below. Most cases of scrapie are now detected through the TSE testing programme. If initial tests suggest that your animal was affected with scrapie or if BSE cannot be excluded, APHA will notify you and arrange to visit your farm. In all cases where scrapie is suspected or confirmed or BSE cannot be excluded, APHA will gather details about the case which are used to study the disease.

If scrapie is confirmed or if BSE cannot be excluded on initial tests, APHA will decide how to apply compulsory control measures to your flock or herd through the Compulsory Scrapie Flocks Scheme (CSFS). These may include a combination of the following controls for two years:

• restrictions on the movement of sheep and goats, and their semen, ova and milk, on and off your holding
• genotyping (of sheep)
• killing of genetically susceptible animals (i.e. some sheep and all goats) and destruction of their semen and ova
• testing of culls and fallen stock

APHA will provide you with detailed guidance on your legal obligations under the CSFS.

Compensation

APHA will pay compensation for a sheep or goat killed as a scrapie suspect:

• if scrapie is confirmed by the laboratory, the compensation payable is £30 for a cull animal and £90 for any other animal
• if scrapie is not confirmed by the laboratory, the compensation payable is either the amount above or the "market value" (disregarding the animal's condition) to a maximum of £400

APHA will also pay compensation for any other animals in the flock or herd which are compulsorily killed, or their products compulsorily destroyed, through the CSFS, following the confirmation of scrapie or where BSE cannot be excluded.

Biosecurity

Biosecurity is about being aware of the ways disease can spread and taking every practical measure to minimise the risk of disease spreading. The advice details practical things you can do on your farm to help prevent the introduction and spread of scrapie to and from your animals.

Reducing the risk of classical scrapie

You should take precautions to reduce the risk of introducing scrapie into your flock or herd, as scrapie control measures will be applied to the whole flock or herd. However, where scrapie has been introduced we advise taking precautions to reduce the number of animals infected. This applies in particular to goat herds as goats appear to be more uniformly susceptible to classical scrapie.

Breeding for resistance

The genetic make-up of sheep affects their susceptibility to classical scrapie. NSP1 Type 1 (ARR/ARR) sheep are most genetically resistant to classical scrapie. You can discuss genotyping and breeding sheep for resistance with your private veterinary surgeon.

Purchasing animals

Classical scrapie is caused by an infectious agent. Most flocks or herds which contract scrapie have purchased an infected animal which is incubating the disease. You are advised to source either genetically resistant replacements or animals from flocks and herds which have been monitored for the past three years and in which scrapie has not been identified.

Milk/colostrum

Classical scrapie can also be spread through colostrum and milk. If you purchase replacement colostrum or milk, you should only do so from flocks and herds which have been monitored for the past three years and in which scrapie has not been identified, particularly if you have genetically susceptible animals. In intensively managed flocks containing genetically susceptible animals, you can reduce the risk of spreading classical scrapie by avoiding using pooled colostrum and milk. In both cases cow colostrum and artificial milk replacers should be considered as an alternative.

Lambing/kidding

Classical scrapie is spread from an infected dam to her offspring and other sheep or goats. Birth fluids and afterbirth from infected animals will contaminate pastures or buildings. Contact between sheep and goats and afterbirths should be kept to a minimum. Prompt removal of afterbirths and regular cleaning and disinfecting of buildings used for lambing or kidding may reduce the risk of exposure of animals to the scrapie agent. This will help to control the disease but it is unlikely to remove all the contamination in the environment.

Cleaning/disinfecting

It is possible that the scrapie agent is also spread in other ways e.g. faeces or urine. The scrapie agent is known to persist in the environment for several years. It is resistant to most commercial disinfectants although thorough cleaning and disinfection of buildings are likely to reduce the level of infection. You are advised to ensure that any disinfection is carried out in accordance with Environment Agency or Scottish Environmental Protection Agency requirements.

Reducing the risk of atypical scrapie

It is not yet known whether atypical scrapie spreads from animal to animal. Some of the biosecurity measures detailed above may also reduce the risk of purchasing atypical scrapie. However, the genetic susceptibility of sheep to atypical scrapie differs from that of classical scrapie in that atypical scrapie has been reported in NSP Type 1 sheep.