Hobby Farms

Eradicate Scrapie

- ag bites rural news and advice from across the country — Anna O’Brien, D.V.M.

Scrapie is a fatal, degenerati­ve neurologic disease that affects sheep and goats. It’s one of a handful of diseases classified as a transmissi­ble spongiform encephalop­athy. TSE may ring a bell. These diseases are also known as prion diseases.


Prions are thought to be the causative agent but are still little understood. They aren’t living infectious organisms such as bacteria or viruses but rather abnormal pathologic agents that seem to induce abnormal folding in normal cells. This leads to holes in the tissue, which is usually the brain.

In severe cases, the tissue resembles a sponge, hence the term “spongiform.” Mad cow disease, or bovine spongiform encephalop­athy, is probably the most familiar prion disease. Chronic wasting disease of elk and deer is another prion disease.


But back to brains, specifical­ly sheep and goat brains. Scrapie has impacted the U.S.’s small ruminant industry for several decades, first identified in a herd in 1947. The

National Scrapie Eradicatio­n Program was developed by the USDA and its name says it all. However, eradicatio­n is a tall order, and scrapie is a tricky disease.

For one, scrapie has a long incubation period. Animals typically show clinical signs two to five years after initial infection. Secondly, some animals can be infected and transmit the disease but don’t show signs themselves. Thirdly, diagnosing scrapie is done primarily by sampling the brain, which means the animal must be sacrificed (live animal sampling can be done via lymph node sampling, but this is also invasive).

These factors together make scrapie a challenge to identify and eradicate. To accomplish this, the USDA needs your help.

Clinical signs associated with scrapie are neurologic due to the damage within the central nervous system. Affected animals may progressiv­ely become nervous or aggressive. Some will intensely rub themselves on solid objects, as if they were extremely itchy. This is where the name “scrapie” comes from, since they rub so hard, they scrape and damage their wool and skin.

They may have tremors, press their heads on solid objects or stare at the sky. Significan­t weight loss is also common.

No treatment exists for infected animals, so the progressiv­e nature of these signs ends in the inability to move and subsequent death. The degenerati­ve and untreatabl­e nature of this disease illustrate­s why it’s important both for the health of the immediate flock and the small ruminant industry to eradicate it.

The current eradicatio­n program is based on identifyin­g animals to ease tracing if needed and surveillan­ce, mostly done at slaughter. Small ruminant farmers are strongly encouraged to participat­e in official identifica­tion and are required to do so if their animals cross state lines.

USDA’s Animal and Plant Health Inspection Service provides the official tags for a small fee. An animal’s age and its ultimate use (sale, slaughter, etc.) should go into the decision whether to participat­e. A handy decision tree is available online: https://bit.ly/4769xvO

Surveillan­ce is the second part of the program. If you have an animal showing possible signs of scrapie or an adult sheep or goat that dies or is euthanized from these signs or unknown causes, contact your veterinari­an. He or she can then contact your local APHIS Veterinary Services vet who will be able to provide supplies for official sample collecting.

The annual sampling goal set for the U.S. is 40,000 samples collected from sheep and goats 18 months of age or older to help find the final cases of scrapie and stamp out this disease.

 ?? ?? The first case of scrapie in a goat in the United States was reported in 1969.
The first case of scrapie in a goat in the United States was reported in 1969.

Newspapers in English

Newspapers from United States