Scrapie in Sheep: Everything You Need to Know

What is Scrapie?

Scrapie is a degenerative disease of the Central Nervous System (CNS) which is fatal, affecting sheep and goats. It is a type of disease known as a Transmissible Spongiform Encephalopathy and has a worldwide presence. It first emerged in Europe and the United Kingdom 250 years ago. Flocks can suffer from as much as 10-20% mortality rates due to scrapie, introducing a massive economic burden for the industry.

Scrapie occurs in both male and female sheep, generally emerging between 2-5 years of age with appearance rare before 18 months of age. However, scrapie is fairly rare in the UK with only 17 confirmed cases in 2018 and 16 confirmed cases in 2019.

What causes scrapie in sheep and goats?

A transmissible agent called a prion, which is an abnormally-folded protein, is the cause of scrapie. Historically there has also been evidence to suggest a genetic element which increases susceptibility to the disease. There is evidence to suggest that scrapie can be transmitted from animal to animal. This can be through the environment and from mother to offspring.

Will I lose money if my flock has scrapie?

Scrapie can lead to economic losses for individual farmers and whole country market losses. Losses can stem from decreased value of breeding stock, even with very low incidence. Government funding of eradication and treatment, and destruction of infected animals also causes economic loss. Scrapie has led to limited trade and restrictions of live sheep, embryos and other ovine products.  

What are the signs of scrapie?

Due to the degradation of the CNS, animals exhibit behavioural changes. The onset of symptoms is typically accompanied by a slight change in behaviour such as vacancy, aggression or nervousness. You might see a tremor of the head and neck. Incoordination and motor abnormalities give the animal a trotting gait and a bunny hop of the back legs. This progresses to loss of use of the hindlegs. These symptoms eventually culminate in a loss of activity and death.

Scratching of the skin is the tell-tale sign in scrapie and is what it is named after. You can spot this by observing sheep nibbling themselves or rubbing against things. They might have skin damage or wool loss. A good way to spot this is also by observing their environment, spotting wool tags of branches, fences and the ground. Goats tend to use their environment to rub against less, but do scratch themselves a lot with their horns and hooves. Other diseases such as sheep scab can cause itching, so make sure to rule those out.

What to do if you think your animal has scrapie

It is strongly advised that you seek out your vet if you suspect scrapie, as it is not the simplest disease to diagnose. It necessitates a post mortem of the affected animal combined with laboratory tests. If your animals are diagnosed with scrapie, then unfortunately there is no current treatment. It is hard to tell how prevalent it is within the flock, as the incubation period tends to be fairly long. If an animal is infected at birth, they may not show signs until age 2.

If confirmed, you must inform the APHA or DEFRA as scrapie is a notifiable disease. You can do this here. You must also join the Compulsory Scrapie Flocks Scheme (CSFS). APHA will contact you regarding how to deal with any infected animals. Usually, you can not move any infected animals unless they are going directly to slaughter for human consumption. Even then, they have to go to specific abattoirs if over 18 months where scrapie can be tested for. If animals die or are euthanased on farm, you must test for scrapie.

If there are no cases for 2 years, the restrictions are removed. Sheep and goat transport and husbandry can then be resumed. For more advice, the DEFRA website has guidance on how to spot and report scrapie.