Clinical aspects of disease in 22L or RML scrapie-infected C57BL/10 and tg44+/+ mice.

aClinical signs were similar in infected tg44+/+ and tg23+/+ mice infected by IC inoculation with either 22L or RML scrapie strains as described in the methods. End-stage neurological disease in these mice was characterized by profound weakness, hypoactivity and reduced ability to eat or drink, requiring euthanasia. In heterozygous tg44+/− and tg23+/− mice clinical signs were similar, but less severe and more erratic. However, most heterozygous mice developed dermatitis, bladder distention, infection and tumors requiring euthanasia prior to development of end-stage neurological disease.bClinical signs were present on an erratic basis initially, but became more consistent and severe over time.cMost = 85–100%; few = 0–15%.