Scrapie is a progressive disease of sheep and goats which affects the brain and nervous tissue. Like BSE, it is one of the Transmissible Spongiform Encephalopathies (TSE). It has a long incubation period and is a notifiable disease in the United Kingdom. The disease is highly contagious and spreads at lambing time in the placental fluids and it is possible for new born lambs from an infected ewe to pick up the disease at birth. The causal agent may also be transmitted via the oral or respiratory route and possibly in faeces.
Genotyping and Breeding for resistance (Hampshire Downs)
Some sheep are more genetically resistant to classical scrapie than others. The HD breed only has the three more resistant genotypes with ARR/ARR sheep being more resistant than ARR/ARQ sheep who, in turn, are more resistant than ARQ/ARQ sheep. You can use genotype testing to identify scrapie resistant sheep and then try to breed animals that are more resistant. If you wish to export sheep the samples have to be taken by a vet and submitted to an approved laboratory. In other cases, you can take the samples yourself. Talk to your vet to find out more about how to do this.
Scrapie Monitoring Scheme
Flock masters wishing to export breeding sheep and goats throughout the EU may have their flock or herd monitored under the provisions of the Scrapie Monitoring Scheme administered by SRUC. Registered flocks and herds undergo an annual flock inspection and brains from a proportion of adult animals are screened for the disease. Members of the Scrapie Monitoring Scheme must ensure that any fallen sheep and certain culled animals over 18 months of age are tested for evidence of Scrapie. For more details on this scheme click here
Signs of scrapie
There are 2 types of scrapie – classical scrapie and atypical scrapie.
Classical scrapie usually affects animals aged between 2 and 5 years old. It is highly contagious and can be spread via colostrum and milk, and via contamination of buildings, bedding, equipment (feeding troughs) by infected animals, and also by contaminated pastures where animals have given birth.
Atypical scrapie usually affects animals older than 5. Cases usually occur in individual animals and it is believed to be little or not contagious at all.
Animals affected by scrapie can have a range of clinical signs they can-
- become excitable
- have drooping ears
- act nervously or aggressively
- lag behind other animals
- show signs of depression or a vacant stare
- tremble (this usually affects the head)
- have an unusual high stepping trot
- lack coordination and stumble or stand awkwardly
- have weak hind legs or be unable to stand
- unable to stand
- weight loss – this is a late clinical sign
- Additionally, their skin may be irritated which can mean they:
- repeatedly rub their heads and bodies against fences, posts or hay racks
- repeatedly scratch their flanks – horned animals may use their horns
- nibble or grind teeth when rubbing themselves or when rubbed firmly on the back
- repeatedly scratch their shoulders or ears with a hind foot
- nibble the feet, legs or other parts of the body in an agitated way
- have excessive wool loss or skin damage
Scrapie will eventually kill any animals that are affected by it.
Preventing and controlling scrapie
You can help prevent the disease by practising strict biosecurity on your premises.
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.
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 3 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 3 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.
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.
What happens if you suspect scrapie?
If you suspect scrapie you should notify your local government vets who will visit your farm and investigate. For more details on what to do if you suspect scrapie click here https://www.gov.uk/guidance/scrapie