Animal Diseases

Scrapie

Scrapie is a fatal degenerative disease of the central nervous system. It afflicts sheep and goats. It is in the same family of diseases as bovine spongiform encephalopathy (BSE or Mad Cow Disease) in cattle and chronic wasting disease (CWD) in deer.

Cause and transmission
Clinical signs
Diagnosis
National Scrapie Eradication Program
Voluntary Scrapie Flock Certification Program
Identification
Moving sheep and goats
Other resources

Cause and transmission

Scrapie is a condition in which sponge-like holes develop in the sheep and goat brain.  Most scientists believe that scrapie is caused by prions – an abnormal form of a normal cell protein.  It appears to spread most commonly from an infected, often normal looking ewe to her offspring and other lambs that come in contact with the placenta and placental fluids.  The environment can become contaminated and remain so for years, serving as a source of infection to susceptible animals long after these materials have been removed.  Although infection likely occurs at or shortly after birth, scrapie is a degenerative disease and signs usually develop 2 to 5 years later.  Animals may live 6 months or longer after onset of signs, but there is no treatment, and death follows a progressive course of disease.

Susceptibility in sheep is linked to genetics, and genetic testing is available to aid in management of this disease.  Genetic susceptibility in goats is not well understood, therefore all goats are considered susceptible when evaluating exposure risks for this species.

There is no evidence of a human health risk.

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Clinical signs

Clinical signs of scrapie are initially mild and progress in severity over weeks to  months.

Signs vary widely among individuals and may include:

• Subtle changes in behavior and temperament, especially in early stages
• Scratching and rubbing against fixed objects
• Loss of coordination
• Abnormal gaits, including high-stepping with the forelegs, hopping, and swaying the back end
• Weakness
• Weight loss
• Biting feet and limbs
• Lip smacking

Infected animals may appear normal at rest, but if startled or stressed, tremble or fall down as if in a convulsion.

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Diagnosis

Veterinarians can diagnose scrapie in live animals by biopsy of lymph tissues from the inside of the third eyelid or rectal mucosa. Most often, however, it is diagnosed by examining brain tissue under a microscope after death.

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National Scrapie Eradication Program

The United States Department of Agriculture’s (USDA) Scrapie Eradication Program goal is to eradicate scrapie and have the United States declared scrapie-free by the World Organization for Animal Health by 2017.  Achieving this goal will boost producers’ economic viability by increasing opportunities for exports, increasing value of animals, and decreasing production costs.  Although there is no evidence to suggest scrapie is a human health concern, eradication can increase consumer confidence in a healthy food supply.  The main tools in the program are animal identification to facilitate rapid identification of exposed animals and premises, surveillance testing among live animals and post-slaughter, and genetic-based flock cleanup plans.

See National Scrapie Education Initiative for more information.

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Voluntary Scrapie Flock Certification Program

The United States Department of Agriculture’s (USDA) Scrapie Flock Certification Program provides producers with a framework for protecting their animals from scrapie and increasing economic opportunities for sales.  Sheep and goat owners can choose to apply for participation in various categories, depending on their goals.  Producers exporting live sheep/goats or embryos/semen will find participation to be especially useful and possibly required by receiving countries.

See the USDA website for more information.

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Identification

Most sheep and goats in Wisconsin need official identification whenever they move to or from the farm. This includes, but is not limited to, moving to:

• Markets
• Fairs and exhibitions
• Other farms
• Veterinary clinics
• Other states

All sheep and goats moving from the farm of origin need official identification.   The rare exceptions include:

• Neutered sheep and goats under 12 months of age
• Sheep and goats under 12 months of age going directly to a slaughter establishment for slaughter  (Note:  private homes and farms and most markets are NOT slaughter establishments)

Be sure to check with event organizers as individual fairs, exhibitions, and markets may have additional identification requirements.  If moving animals out of Wisconsin, contact destination states or countries for any additional identification or other import requirements.  Click here for other states’ and countries’ contact information.

For acceptable forms of identification, see brochure:  Official Individual Identification Requirements for Sheep and Goats in Wisconsin (2 page PDF)

Scrapie tags are available from the USDA Veterinary Services Wisconsin office.  Download an order form or call
1-866-USDA TAG (1-866-873-2824).

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Moving sheep and goats

Requirements for moving sheep and goats within and into Wisconsin

Requirements for exporting sheep and goats from Wisconsin to other states or countries

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Other resources

Wisconsin Department of Agriculture, Trade and Consumer Protection

Wisconsin Administrative Rule – see ATCP 10.69 – 10.70 for sheep and ATCP 10.76-10.77 for goats

U.S. Department of Agriculture-APHIS – scrapie disease information

Wisconsin office of USDA-Veterinary Services

Scrapie tags order form - from the USDA Veterinary Services Wisconsin office (Or call 1-866-USDA TAG
(1-866-873-2824)

National Scrapie Education Initiative

American Sheep Industry Association

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United States Department of Agriculture Animal and Plant Health Inspection Service Safeguarding American Agriculture

This material was made possible, in part, by a Cooperative Agreement from the United States Department of Agriculture's Animal and Plant Health Inspection Service (APHIS). It may not necessarily express APHIS' view.