How to recognise scrapie
Most cases of classical scrapie occur in animals aged two to five years old. Although classical scrapie is rarely seen in sheep and goats aged less than one year or more than five years, age alone cannot be used to rule out the presence of disease. Atypical scrapie is detected more commonly in animals aged over five years.
Clinical signs of classical scrapie appear a long time after infection and cases generally appear singly in a flock. Occasionally several cases can occur over a short period of time, particularly in genetically susceptible animals (i.e. some sheep and all goats) born at about the same time and possibly to the same dam or sire. Multiple cases are more likely where animals are kept indoors. Atypical scrapie cases generally occur singly.
Scrapie cases can occur at any time of year but stress can cause the clinical signs to appear. Cases are more easily identifiable at times when animals are collected for management purposes such as lambing, weaning or tupping.
Clinical signs of scrapie
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;
- depression or vacant stare.
- 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;
- standing awkwardly;
- weak hind leg;
- unable to stand.
Later clinical signs
There is much more detailed information about the clinical signs of scrapie on the Veterinary Laboratories Agency (VLA) website. You can obtain a DVD on the clinical signs of scrapie from Animal Health.