NASHVILLE, Tenn. — In addition to interstate transport rules for sheep and goats, Tennessee now has similar emergency rules on movement and certification of those animals within its borders, designed to keep scrapie out of local flocks and herds.

Scrapie is a transmissible spongiform encephalopathy (TSE), part of the same family of diseases such as bovine spongiform encephalopathy (BSE), or Mad Cow, in cattle and chronic wasting disease of wild elk and deer.

Dr. Sarel van Amstel, a University of Tennessee large animal clinical sciences professor of internal medicine, said scrapie is a degenerative disease caused by a non-DNA protein, accumulating in the brain and causing a neurological disorder and death. The good news is how uncommon scrapie really is in the Southeast.

“It’s not a thing that we see every day,” van Amstel explained. “I’ve been here 11 years, and I’ve only seen one case.”

As of Aug. 31, according to the USDA, 21 states had scrapie-infected flocks, concentrated mostly in northern and upper Midwestern states. In the Midwest, Ohio had 25, Illinois and Indiana each had six, Iowa had five, Michigan had four and Kentucky had one flock.

Scrapie shows up in sheep more than goats. Tennessee is second only to Texas in meat goats, but ranked 31st for sheep in the United States in the 2002 ag census. Not surprising, then, that there are no clinical cases of scrapie in Tennessee.

“In many instances, when it’s been reported in goats, at some point in their lives they’ve been found to have been commingled with sheep,” said State Veterinarian Dr. Ron Wilson, who added many Tennessee sheep exist by virtue of the state’s active 4-H program.

The emergency intrastate rule enacted by Tennessee Department of Agriculture on Aug. 30 will become permanent at the end of the year. Basically, it will require goat and sheep owners transporting animals elsewhere in the state to first register and ID the ruminant by tagging, as is already required for movement across state lines or for exhibition at fairs and shows.

For goats, all that are registered breeding animals, dairy goats, show goats and those that have commingled with sheep are required to be registered. All sheep must be registered, except for non-exhibition wethers (castrated lambs younger than 18 months).

Wilson said the rule is to govern change of ownership, to make an infected animal easier to trace back to its source flock or herd.

“If you don’t have adequate records in terms of identifying those animals, of showing who bought and sold them, they result in dead ends where you can track the disease,” he explained.

For the most part, van Amstel said scrapie is transmitted from mother to offspring through the placenta. The protein can lie dormant for several years, though lambs can begin displaying symptoms at 2 1/2 years of age. There is also a genetic component to the disease, which Wilson said makes ID tagging even more valuable. Researchers are trying to isolate genes proven resistant to the protein’s effects.

It’s possible for the disease to spread from animal to animal through close contact or overcrowding. In Iceland, van Amstel said scrapie is a problem partly because of keeping the animals penned close inside where it is warm for long periods of time.

As with BSE, van Amstel said there is no conclusive evidence scrapie – or any TSE – can be transmitted from animal to human. For years there has been speculation linking BSE to the human equivalent Creutzfeldt-Jakob Disease, but this has not been proven.

“Essentially, there’s no practical test in the live animal,” van Amstel said. “It is usually confirmed in necropsy” from the brain or lymphatic tissue.

Wilson added there is a test that can be performed on tissue from the live animal’s third eyelid, but it is of limited use since a negative result doesn’t necessarily mean the animal is disease-free.

Both said symptoms of scrapie manifest in severe itching, to the point where a sheep will tear out clumps of its own wool. Clinically ill animals may also show abnormalities in their rear-leg gait and display noticeable weight loss.

A farm that has hosted an infected animal is difficult to rid of the protein, van Amstel said – it can survive for years. Only steam at high temperatures and strong chemicals such as sodium hydroxide seem to be effective killing agents.

More about scrapie and national patterns can be found at www.aphis.usda. gov/vs/nahps/scrapie and Tennessee regulations are at state.tn.us/agricul ture/regulate/animals/index.html

For more about ruminant identification, call Wilson’s office at 615-837-5302 or USDA Veterinary Services at 615-781-5310.