I believe that scrapie has been endemic in the British sheep population
for a long time (more than 150-200 years). Does scrapie exist in
Australian and New Zealand sheep, as I would have thought their animals
would have originated in Britain.
Also, I believe that it is not just cows that became infected. Certain
zoo animals fed infected meal have also died of BSE, as have cats from
eating infected canned cat food (dogs also??).
I was told that the infective material (in brain pastes) isolated from
cows differs from the original scrapie form. It is more infective and
more resistant to high temperatures, so does anybody know how many
different forms are out there? It seems a bit premature to assume humans
are immune to this disease.