Scrapie is a disease that has been around for a few centuries, but opinions differ (often loudly and vehemently) as to what exactly causes it. Prions are the most widely held opinion at this time, but there are other opinions that this disease may be related to extremely toxic, industrial induced conditions over the last few centuries. Whatever the cause, it is thought to be transmitted from mother to lamb, and the symptoms often don't show up until the animal is 5 years old. The only way to absolutely test the animal is to test brain tissue, which requires the sheep's death in order to test. The followers of the prion theory believe that testing for certain genetic codons and culling animals without those specific codons can reduce the chances of contracting Scrapie. This may be so, but culling for certain codons may eliminate many rare and ancient breeds of sheep, and may result in losing valuable genetics. It is a poor choice for saving rare breeds. While scrapie is not currently found in Australia or New Zealand, many Australian and NZ shepherds are selecting for sheep WITHOUT the "recommended" codons, theorizing that Scrapie will then show up sooner and can then be eradicated from the flock sooner. With all these different opinions from experts on what to select for, it's obvious that the only thing we know for sure is that nobody knows anything for sure about the cause of Scrapie, so it cannot be said with absolute certainty that any particular genetics should be selected for. Scrapie has never been found in Soay sheep to my knowledge, and certainly has never been found in Soay sheep in North America. The Voluntary Scrapie Monitoring Program requires that our flock is inspected yearly by a State Veterinarian, and that we use specific eartags with tracking numbers in the ears of our sheep. We have been enrolled in this program since the spring of 2000. Since that time the US government has implemented a mandatory program, which does not require an inspection, but does require that sheep sold are tracked. We are not required to be in the mandatory program because the Voluntary Program we are enrolled in goes above and beyond the mandatory program.Ovine Progressive Pneumonia, also known as OPP, is a slow acting disease that has been described as similar to AIDS in humans. There is no known cure; the only way to rid your flock of infected animals is to destroy each infected sheep. OPP is most often passed from mother to lamb via milk, but can be transmitted from sheep to sheep in a flock. While there are expensive tests for lambs of several months of age, the most accurate tests are from sheep of at least one or two years of age. This disease shows no symptoms in young sheep; if they are infected, it will take several years for the symptoms to show up, resulting in weakened sheep and eventual death. Our adult sheep are now tested yearly, and our flock tested negative for OPP, including all of our elderly ewes, several of which are 10 or 11 years old. There may be a link between OPP and CAE (found in goats), which indicates that if you ever need to bottle feed a lamb, it's a good idea to get goat's milk from a herd certified free of CAE.by Cynthia B. Wolf of University of Minnesotaby Gates' Practical Guide to Sheep Disease Management, Pipestone Veterinary Clinicby Washington Animal Disease Diagnostic LaboratoryMark Purdey's alternative research and data on BSE, Scrapie and related topics.Mainstream prion theory and genetic codon testing provided by the US Government.Why selecting for the "proper" codons is unlikely to eradicate scrapie, and may makeit more insidious.Several Scottish views on the NSP in the UK.The case against selecting for scrapie-resistant genotypes in rare breeds of sheep, by two British Veterinarians.