- Spread is usually from ewe to lamb : by drinking of amniotic fluid in utero; by transfer of lymphocytes from colostrum/milk /nasal secretions/placental material into skin abrasions.

- Spread was acclerated in Scotland by inoculation of a contaminated Louping ill vaccine composed of formalin-fixed brain -this stimulated Scrapie research.

- Scrapie has been exported in carrier sheep from the UK to Canada, Australia, USA and India.

- No humans have developed CJD by contact with infected sheep or eating sheep offal/ brains.