Scrapie facts for kids
Scrapie is a serious and deadly brain disease that affects sheep and goats. It's a bit like "Mad cow disease" (also known as Bovine Spongiform Encephalopathy or BSE), which affects cattle. Scrapie was first noticed a long time ago, in 1732. Scientists believe tiny, misfolded proteins called prions cause it. These prions damage the brain and nervous system.
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What is Scrapie?
Scrapie is a type of disease called a "transmissible spongiform encephalopathy" (TSE). This long name means it's a disease that can be passed on, and it makes the brain look like a sponge with tiny holes. When animals get Scrapie, their brains slowly get damaged. This leads to problems with how they move and behave.
How Scrapie Affects Animals
Animals with Scrapie show several signs as the disease gets worse. These can include:
- Intense itching, causing them to rub or scrape against things (which is how the disease got its name!).
- Loss of coordination, making it hard for them to walk straight. They might stumble or fall.
- Changes in behavior, such as being more nervous or aggressive.
- Weight loss, even if they are eating normally.
- Tremors or shaking, especially in their head and neck.
Sadly, once an animal starts showing signs of Scrapie, there is no cure. The disease always leads to death.
The Role of Prions
Scrapie is caused by unusual agents called prions. Prions are not like bacteria or viruses. They are normal proteins that have folded into the wrong shape. Once a prion is misfolded, it can cause other normal proteins to also misfold. This chain reaction creates more and more abnormal prions. These bad prions then build up in the brain, causing damage.
How Prions Spread
Scientists believe Scrapie prions can spread in a few ways:
- From a mother sheep or goat to her lambs or kids, usually around birth.
- Through the environment, where prions might stay in the soil for a long time.
- When healthy animals come into contact with infected tissues or fluids from sick animals.
It's important for farmers to keep their flocks healthy and watch for any signs of Scrapie.
History of Scrapie
Scrapie has been known for a very long time. The first clear description of the disease dates back to 1732 in Great Britain. For centuries, farmers have seen sheep with these strange symptoms. Over time, scientists began to study the disease more closely. They wanted to understand what caused it and how to stop it from spreading. The discovery of prions in the 20th century helped explain how diseases like Scrapie work.
Preventing Scrapie
Because there is no cure for Scrapie, preventing its spread is very important. Farmers and veterinarians work together to control the disease. Some ways to prevent Scrapie include:
- Testing animals to find out if they carry genes that make them more resistant to the disease.
- Carefully managing breeding programs to reduce the risk.
- Following strict rules about moving animals between farms.
- Removing infected animals from the flock to prevent further spread.
These efforts help keep sheep and goat populations healthy around the world.
Images for kids
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Human prion protein, residues 125–228, created from protein database (PDB) entry 1QM3. The coloring illustrates the subdomains, that are proposed to initiate the conversion from the normal cellular to the scrapie form by slow motions.
See also
In Spanish: Tembladera para niños
