[Diagnosis of transmissible spongiform encephalopathies in animals]

Histopathological examination of the central nervous system is essential for the confirmation of a TSE diagnosis. Typical lesions are spongiform changes of the grey matter, intraneuronal vacuoles in particular nuclei of the brain stem, gliosis and neuronal degeneration. The nature of the lesions is similar between species. However, the variation in the distribution and severity of the changes is striking. Even more reliable than histopathology is the detection of disease-specific protease-resistant prion protein (PrPSc) using immunohistochemistry. The so-called "rapid tests" allow detection of PrPSc in unfixed tissues and are mostly used for the screening of risk populations and slaughtered animals.