Scrapie eradication efforts continue

Posted: Thursday, February 7, 2013 11:50 am

AUSTIN - The Texas Animal Health Commission (TAHC) continues to work with the Texas sheep and goat industries toward the eradication of Scrapie. Texas currently leads the nation in sheep and goat production. A common goal of the US Sheep Industry and the American Sheep Industry (ASI) is to eradicate Scrapie from the US borders by 2017.

To help achieve this goal, the USDA is considering a proposed rule that would make the identification requirements for goats similar to those currently in place for sheep, as well as possibly expanding surveillance efforts for Scrapie in goats. Once the disease is eradicated, the US would then seek recognition as Scrapie-free in accordance with the World Organization for Animal Health. (OIE)

Texas leads the nation in sheep and goats production. Since 2009, there have been no confirmed cases of Scrapie in Texas. The last big spike in Texas Scrapie cases was in 2006 with 9 infected herds.

According to USDA regulations, Texas must conduct adequate Scrapie surveillance by a collecting a minimum of 598 sheep samples annually. In 2012 there were 1,050 samples collected from animals with Texas tags.

Dr. Dee Ellis, State Veterinarian, said, "Texas has made significant progress in battling this disease. The Scrapie Program has proven to be successful in Texas. Fighting this disease and implementing an animal identification program has worked." To date, Texas has 30 participating flocks enrolled in the Scrapie Flock Certification program.

Nationally, in 2005, there was a peak in Scrapie numbers. In the last fiscal year, for the first time ever, there were more Scrapie field cases in goats than in sheep. In fiscal years 2008 and 2011, two significant Scrapie outbreaks occurred in goats in volving a total of 18 positive goats.

The National Scrapie Eradication Program continued to make excellent progress in fiscal year 2012. In FY 2012, the percent of cull sheep found positive at slaughter decreased. This measure of prevalence decreased 96.2 percent since slaughter surveillance started in FY 2003 and 24.7 percent, respectively since FY 2011. Additionally, there was a 47% decrease in the number of infected and source flocks identified during FY 2012 compared to the previous fiscal year.

Scrapie is a degenerative disease of the nervous system that falls into the category of Transmissible Spongiform Encephalopathies (TSE). The disease is caused by a transmissible prion or abnormal protein which is very stable in the environment. Traditional blood tests are not reliable to diagnose Scrapie, so a sample is needed to diagnose it. Currently, no treatment exists for Scrapie. There is no known evidence of Scrapie transmission to humans.

While animals of any age may be exposed to Scrapie, lambs and kids are at the greatest risk of contracting the disease and are often infected by their dams shortly after birth.

Typically, infected animals don't show signs of Scrapie, such as behavioral changes, tremors, and incoordination that progresses to recumbency and death, until they are two years of age or older.

The most effective method of Scrapie prevention is to maintain a closed flock. Raising replacement ewes, purchasing genetically resistant (RR) rams or buying from a certified-free Scrapie flock are other options to reduce the risk the Scrapie. At this time the resistant genetic markers in goats have not been identified, therefore it is important to maintain your sheep and goat herds separately.

Since the incubation period for Scrapie is typically two to five years, producers should record individual identification numbers and the seller's premises identification number on purchase and sales records. These records must be maintained for a minimum of five years. "The success of the Scrapie Eradication Program is tied to producers keeping good records of sales and purchases," said Dr. Ellis.

TAHC rules regulate official identification tags or a registration tattoo be applied to all sheep 18 months of age and older, all breeding sheep, all breeding goats except those commingled with other sheep, and all sexually intact show or exhibition animals.

Producers should notify the Texas Animal Health Commission (800-550-8242) or the USDA-Austin Office (512-383-2400) if they have a sheep or goat over 18 months with neurologic signs such as incoordination, behavioral changes, or intense itching with wool loss. Producers may order Scrapie identification tags by calling 866-873-2824. For more information, please visit our web site atwww.tahc.texas.gov or give us a call.

The Texas Animal Health Commission (TAHC) is one of the oldest state regulatory agencies. TAHC was founded by the legislature in 1893 with a mission to combat fever ticks that plagued the Texas Cattle Industry. Today, the agency works to protect the health of all Texas livestock including: cattle, equine, sheep, goats, swine, poultry, exotic livestock and fowl.