Discriminatory immunohistochemistry on an unusual goat TSE case. Extracellular accumulation of PrPd in the brain was revealed with both Bar224 (a) and 12B2 (b) PrP antibodies. IHC and haematoxylin counterstaining, ×4. Intraneuronal PrPd deposits in the olivary nucleus were prominent when labelled with Bar224 (c) but absent when incubated with 12B2 antibody (d). IHC and haematoxylin counterstaining, ×20. In the retropharyngeal lymph node, however, intracellular PrPd deposits were labelled with both bar224 (e) and 12B2 (f) antibodies. IHC and haematoxylin counterstaining, ×10.