The first preclinical, noninvasive test for scrapie, a fatal brain disease of sheep and goats, should be available in a few years, thanks to ARS research. Reliable diagnosis of scrapie is the first step to eradicating the disease, which would greatly improve U.S. sheep and goat export opportunities. ARS scientists discovered that the nictitating membrane, or third eyelid, in sheep collects proteins known as prions.
Abnormal prions are the infectious agents believed to cause scrapie.
Until now, scrapie could be confirmed only by examining the brains of dead animals. The researchers also developed a new laboratory-built molecule, called a monoclonal antibody, that detects the presence of the abnormal prions. The test will eventually allow veterinarians to detect scrapie before animals show clinical signs. Only a local anesthetic is needed to sample the eyelid tissue, so the procedure will be inexpensive and safe. ARS has applied for a patent on the test.