Scrapie is a rare, progressive brain disease that affects sheep and goats. Early symptoms of Scrapie can include behavior changes, itching, rubbing against objects, poor balance, and trouble walking. It usually develops slowly over months, and it is most often recognized in adult animals. Scrapie is fatal, and there is no cure or treatment that stops the disease. It may help to know that doctors have studied this condition for decades, and control mainly focuses on testing, flock management, and preventing spread.
How many people live with Scrapie?
Scrapie is a disease of sheep and goats, not people, so the estimated number of people living with scrapie worldwide is 0, with no known human cases reported (CDC, 2024). In the United States, the estimate is also 0 people, because scrapie has not been identified in humans there either (CDC, 2024; USDA APHIS, 2024).
Overview
ScrapieSymptoms
Scrapie affects sheep and goats, causing behavior changes, itching with rubbing against objects, and an unsteady walk. As scrapie worsens, affected animals may tremble, lose weight despite eating, and have trouble standing.
Outlook and prognosis
Scrapie affects sheep and goats, not people. Even after exposure, scrapie has not been shown to cause illness in humans, so the outlook for people is reassuring, though public health agencies still monitor prion diseases carefully.
Causes and risk factors
Scrapie is caused by misfolded prion protein in sheep and goats, not by lifestyle. Risk rises with certain inherited prion gene variants and exposure during lambing or through contaminated placentas, fluids, or environments. It is not known to affect humans.
Genetic influences
Genetics matter a lot in scrapie: variants in the PRNP gene strongly affect an animal's risk, and selective breeding can lower the chance of disease in sheep flocks. Genetics is only part of the picture, because exposure also matters.
Diagnosis
Scrapie is diagnosed mainly from clinical signs and the animal's history, then confirmed with lab testing of brain or lymph tissue. In many cases, a definite diagnosis of Scrapie is made after death.
Treatment and drugs
For Scrapie, care focuses on flock management rather than medicines. Animals with Scrapie are usually isolated and humanely culled to limit spread. Testing, movement controls, cleaning, and breeding for genetic resistance help protect the rest of the flock.
Symptoms
Symptoms of scrapie usually appear slowly, often in adult sheep or goats that had seemed well for a long time. Early on, this might look like mild itching, small behavior changes, or a gait that seems a little off. The early symptoms of scrapie can be easy to miss at first because they may resemble more common problems such as parasites, injury, or poor condition. As the disease progresses, the changes become more noticeable and do not improve.
Some animals become unusually nervous, excitable, or withdrawn. They may startle more easily or act less settled during feeding, handling, or movement with the flock.
Persistent itching is a classic symptom of scrapie. Affected sheep or goats may rub against fences, posts, or walls over and over, sometimes enough to damage the fleece or skin.
Repeated rubbing can lead to bare patches, broken wool, or sores on the skin. For many, this can mean visible wear on the shoulders, sides, or hindquarters rather than a simple seasonal shed.
Many living with scrapie develop poor balance and an abnormal gait. They may sway, stumble, high-step, or look clumsy when turning or moving across uneven ground.
How people usually first notice Scrapie?
Scrapie is usually first noticed in sheep or goats when an animal that seemed healthy starts to behave differently, often becoming unusually nervous, excitable, or separate from the flock. The first signs of scrapie often include intense itching with rubbing or scraping against fences or posts, along with tremors, changes in walking, or trouble keeping balance. Because scrapie is a slow, progressive prion disease, these early changes can be subtle at first and gradually worsen over months; it affects animals, and it is not known to infect people.
Types of Scrapie
Scrapie does not affect people day to day, but it can have a major impact on sheep and goats, especially as balance, movement, and behavior gradually change. In practice, the main types of Scrapie are classical scrapie and atypical scrapie, and they can differ in how they spread, which animals are affected, and which signs stand out. Not everyone will see the same pattern, because some animals show itching and wool loss, while others mainly develop unsteady walking or subtle behavior changes.
Classical scrapie
This is the more familiar form and usually spreads within a flock or herd through exposure around lambing or kidding. Animals often develop itching, rubbing, nibbling at the body, wool loss, tremor, and worsening trouble with balance and walking. Over time, weight loss and weakness usually become more noticeable.
Atypical scrapie
This form is less common and is often found in a single older animal rather than spreading clearly through the group. Itching is often mild or absent, while unsteady movement, poor coordination, and changes in posture may stand out more. In many living with atypical scrapie, the signs can be subtle at first and easier to miss.
Can I slow down the onset of symptoms?
No, there is no good evidence that lifestyle changes or medical treatment can meaningfully slow the start of symptoms in scrapie once a sheep or goat is already infected. Research supports prevention at the flock level instead: breeding sheep with more natural resistance, avoiding exposure to infected animals and contaminated lambing or kidding areas, and following veterinary testing and control programs can reduce the risk of spread, but they do not prevent disease in an animal that is already infected. If you are concerned, early veterinary advice and local reporting rules can help protect the rest of the flock, which is useful even though it cannot promise a different outcome for the affected animal.
What genetics can tell you about symptoms
Yes. In scrapie, changes in the prion protein gene, called PRNP, are well known to affect whether an animal is more likely to develop the disease, how long it takes symptoms to appear, and in some cases how severe the illness becomes. Genetics does not predict every detail of symptoms, but it can give useful clues about risk and timing, which is why it is often used in breeding and disease-control programs.
Causes and risk factors
Scrapie starts when an abnormal prion protein builds up in sheep or goats and causes other proteins to fold the wrong way. The main risk factors for scrapie are a susceptible genetic makeup, especially certain PRNP gene patterns, and contact with infected animals or birth tissues. Risk is highest around lambing or kidding because the placenta and fluids can carry a lot of infectious material. Contaminated pens, bedding, and soil can also spread scrapie because the agent can stay in the environment for years. It’s rarely just one factor—it’s the mix that matters, so crowded housing, animal movement, and poor flock biosecurity can raise exposure risk.
What are the most common causes or risk factors?
Scrapie is caused by an abnormal protein that builds up in the body and can spread among sheep and goats. The biggest risk factors are being born to or living with an infected animal, especially around birth when the placenta and birth fluids can carry the protein, and spending time in places contaminated by these materials. Genes also matter, because some sheep and goat families are more likely to get scrapie than others.
Environmental and biological risk factors
Scrapie is an infectious brain and nervous system disease of sheep and goats caused by an abnormal protein. If you are trying to understand how scrapie spreads in sheep and goats, the biggest risks come from exposure around birth and from contaminated surroundings. Risk factors are often grouped into internal (biological) and external (environmental).
Placenta, amniotic fluid, and tissues from an infected ewe or doe can contain large amounts of the scrapie agent. Animals exposed in lambing or kidding areas are at especially high risk.
Lambs and kids born to or kept very close to infected mothers have more chances for exposure. The risk is highest around birth, when contact with fluids and tissues is most intense.
Milk and first milk, called colostrum, from infected mothers can also carry the agent. This can add to early-life risk for newborn lambs and kids.
The abnormal protein that causes scrapie can stay in bedding, soil, pens, and on some equipment for a long time. Because of that, a flock or herd may remain at risk even after infected animals are removed.
Genetic risk factors
For Scrapie, the main inherited factor is the prion protein gene, called PRNP, which affects how easily abnormal prion proteins can build up. When people talk about the genetic risk factors for Scrapie, they are mostly referring to different PRNP patterns passed down in sheep or goats. Risk is not destiny—it varies widely between individuals, and the highest-risk or lowest-risk patterns are best established for classical Scrapie in sheep. Some genetic patterns linked with lower risk for classical Scrapie do not give the same protection against atypical Scrapie.
PRNP gene: Inherited changes in PRNP are the main known genetic driver of Scrapie susceptibility. Small differences in this gene can make it easier or harder for abnormal prion protein to form and spread.
VRQ pattern: In sheep, carrying the VRQ version of PRNP is linked to a high risk of classical Scrapie. Risk is especially high when both inherited copies are VRQ, or when VRQ is paired with another susceptible version such as ARQ.
ARR pattern: In sheep, the ARR version of PRNP is strongly linked with resistance to classical Scrapie. Animals with two ARR copies have the lowest well-established genetic risk, although this does not fully protect against atypical Scrapie.
ARQ and others: Sheep with ARQ, ARH, or AHQ patterns usually have intermediate or strain-dependent risk rather than the highest or lowest risk. The exact effect can vary with the type of Scrapie and the second PRNP copy they inherit.
Goat PRNP variants: In goats, PRNP also affects inherited risk, but the picture is less standardized than in sheep. Variants such as K222 and changes at codon 146 are linked with lower risk of classical Scrapie in several breeds.
Breed background: Some sheep and goat breeds carry certain PRNP patterns more often than others, which can shift inherited risk across a flock or herd. Breed background matters because it changes how common high-risk or lower-risk gene patterns are.
Family lines: Scrapie risk can cluster in related animals because PRNP patterns are passed through families. This does not mean every offspring will be affected, but close genetic lines may share similar levels of susceptibility.
Lifestyle risk factors
For scrapie, the usual human-style lifestyle risk factors such as exercise or ordinary diet are not the main issue. When people ask how lifestyle affects scrapie, the practical concern is husbandry habits that change an animal's chance of exposure to infectious prions. These day-to-day management choices do not create the disease on their own, but they can strongly influence spread within a flock or herd.
Poor handling of lambing areas, placentas, and birth fluids can greatly increase exposure to scrapie prions. Careful cleanup and limiting contact with contaminated materials can reduce transmission to newborns and other animals.
Bringing in sheep or goats without screening, traceability, or quarantine can introduce scrapie into a previously unaffected group. Closed-flock practices and sourcing from low-risk animals help lower this risk.
High stocking density, especially around lambing or kidding, increases contact with contaminated tissues and surfaces. More space and better separation of birthing animals can help limit spread.
Keeping animals with suspect neurologic signs or retaining offspring from affected lines can allow scrapie to persist unnoticed in the flock. Prompt veterinary evaluation, testing, and removal of affected animals reduce ongoing exposure.
Risk prevention
Scrapie does not affect people, so there is no personal risk of catching Scrapie from everyday contact. Prevention is about lowering risk, not eliminating it completely. In practice, preventing Scrapie means protecting sheep and goat herds by reducing exposure, avoiding high-risk breeding, and catching possible cases early. This matters most for farmers, breeders, and anyone buying or moving animals between flocks.
The best way to lower the risk of Scrapie is to avoid bringing infected animals into a flock or herd. Buy sheep or goats only from sources with strong health records and known Scrapie control practices.
In sheep, selective breeding for genetic resistance can reduce the chance that Scrapie will spread through future generations. This is one of the most effective long-term answers for people asking how to prevent Scrapie in sheep.
Scrapie can spread around lambing or kidding, especially through contact with the placenta and birth fluids. Prompt cleanup, safe disposal of afterbirth, and keeping birthing areas clean can reduce exposure for other animals.
Animals with signs that could fit early symptoms of Scrapie, such as worsening itching, behavior change, tremors, or trouble walking, should be separated quickly. Early veterinary assessment helps protect the rest of the flock or herd.
Can you prevent Scrapie?
You cannot fully prevent scrapie in every sheep or goat flock, but the risk can be lowered a lot. The most proven steps are buying animals from low-risk flocks, not breeding from animals that may carry the disease, testing and removing affected animals, and following local rules for cleaning and safely handling birth materials and dead animals, because the cause of scrapie can stay in the environment for years.
Transmission
Scrapie is an infectious disease of sheep and goats, and there is no evidence that it infects humans. It usually spreads within a flock or herd through contact with infected placenta, birth fluids, or tissues around lambing or kidding, and young animals may also be exposed from contaminated pens, bedding, or soil.
When people ask how scrapie spreads, the key point is that it is not highly contagious in the way a fast-moving virus is. Instead, scrapie tends to spread slowly, especially around birth, and it can be hard to eliminate because the infectious material can remain in the environment for years.
When to test your genes
Genetic testing is not used for people because scrapie is a prion disease of sheep and goats, not a human condition. In animals, PRNP genotyping can help guide breeding and flock control, especially in breeding sheep or goats and after a confirmed case or known exposure.
Diagnosis
Scrapie is usually suspected when a sheep or goat develops gradual changes such as intense rubbing, hair loss, trouble with balance, tremors, or weight loss despite eating. It’s natural to worry when symptoms don’t have a clear explanation. The diagnosis of scrapie starts with the animal’s signs and history, but it cannot be confirmed by symptoms alone. Veterinarians and animal health officials use a combination of exam findings, tissue testing, and, in some cases, testing after death to be sure.
A veterinarian looks for itching, wool or hair loss, unsteady movement, tremors, behavior changes, and weight loss. Doctors usually begin with a full exam because these signs can overlap with other nervous system or skin conditions.
The animal’s age, flock or herd history, and any contact with infected animals are important clues. A detailed family and health history can help, especially because some breeds and genetic patterns can affect risk.
Blood work, parasite checks, and other lab tests may help rule out common conditions that can also cause itching, weakness, or weight loss. This step matters because there is no single live-animal screening test that replaces a full evaluation.
In some animals, a small sample of lymphoid tissue such as the third eyelid or rectal tissue can be tested for abnormal prion protein. These tests can support how scrapie is diagnosed, although results may depend on the stage of disease and the animal’s genotype.
How is Scrapie diagnosed?
Scrapie is usually suspected in sheep or goats from the animal's age, behavior changes, trouble walking, itching, and the history of the flock or herd, but these signs alone cannot confirm it because other illnesses can look similar. A definite diagnosis is made by testing tissue for the abnormal protein linked to scrapie, most often in the brain after the animal has died, although some live-animal tests use small samples from the eyelid or rectum. In sheep, genetic testing may also be used to check whether an animal has a higher or lower risk of scrapie, but it does not by itself prove that the animal has the disease.
Stages of Scrapie
Scrapie does not have defined progression stages. This is because it usually develops slowly over a long incubation period, and animals are typically recognized once changes in movement or behavior appear rather than moving through a standard set of named stages. In practice, monitoring focuses on signs such as itching, trembling, poor balance, weight loss, and other early symptoms of scrapie, along with a veterinary exam and flock history. A firm diagnosis usually depends on specialized testing of tissue, often after death, while suspected cases in living animals are followed closely and reported according to animal health rules.
Outlook and prognosis
There is no evidence that scrapie causes illness in people, so there is no recognized human prognosis or mortality pattern associated with it. In the animals it affects, however, the outlook is poor: scrapie is progressive, untreatable, and ultimately fatal once clinical signs appear. Most affected sheep or goats deteriorate over weeks to months, with worsening itching, behavior changes, incoordination, weight loss, and weakness. Death may occur naturally in advanced disease, or animals are often euthanized for welfare reasons once they can no longer stand or eat normally. Because the incubation period can be very long, apparently healthy animals may carry the infection for years before symptoms develop.
Long-term effects
For people asking about the long-term effects of scrapie, it helps to know that this disease affects sheep and goats rather than humans. In affected animals, scrapie gets worse over time and is ultimately fatal, with changes in movement, behavior, and body condition. The long-term picture is often one of gradual decline over months, although the pace can vary. Scrapie is not known to spread to people through normal contact with affected animals.
Animals with scrapie may become unusually nervous, excitable, or hard to handle. Over time, they can seem separated from the flock or react strongly to touch, sound, or routine activity.
Constant rubbing, scratching, or biting at the wool or skin is one of the best-known long-term effects of scrapie. Many animals wear away fleece, damage the skin, or develop bare patches because the itching does not ease.
Balance and coordination often worsen as scrapie progresses. You might notice stumbling, a high-stepping gait, weakness in the back legs, or trouble standing for long periods.
Even if eating seems fairly normal at first, affected animals often lose body condition over time. This can leave them thin, weak, and less able to keep up with feeding, breeding, or daily movement.
How is it to live with Scrapie?
Scrapie is not a human disease; it is a fatal prion disease of sheep and goats, so there is no “living with scrapie” in the usual patient sense. For affected animals, daily life gradually becomes harder as balance, coordination, and behavior change, often with intense itching that leads to rubbing and wool loss, and over time they may struggle to stand, walk, or feed normally. For the people around them, especially farmers and caregivers, the impact is emotional and practical because sick animals need close monitoring, isolation from the flock or herd, and veterinary guidance, and the disease can lead to major losses in breeding stock and farm routines.
Treatment and drugs
Scrapie is not treated with medicines because it is a fatal prion disease in sheep and goats, and there is no drug that can stop or reverse it. Instead, care focuses on confirming the diagnosis, reducing suffering, and preventing the disease from spreading within a flock or herd. Supportive care can make a real difference in how you feel day to day, but for scrapie this mainly means keeping the affected animal comfortable for as long as possible, since signs such as itching, poor balance, and weight loss usually keep getting worse. Treatment plans for scrapie therefore center on veterinary and public health steps, such as removing affected animals, tracing exposed animals, and using breeding programs that lower the risk in future generations.
Can you cure Scrapie?
No, scrapie cannot be cured, and there is no treatment that can stop or reverse it once a sheep or goat has the disease. Care is mainly about keeping affected animals comfortable for as long as possible and protecting the rest of the flock or herd through testing, removing infected animals, and careful breeding to lower the risk in future animals.
Non-drug treatment
For scrapie, there is no proven non-drug treatment that cures an affected sheep or goat. Managing this condition often centers on protecting the rest of the flock, since once signs appear, supportive care does not stop the disease from getting worse. In practice, non-drug care is mostly about control, welfare, and prevention, including steps often discussed under how to prevent scrapie in sheep. A veterinarian and local animal health authorities usually guide these decisions.
Animals suspected of having scrapie should be separated from the rest of the flock as soon as possible. This lowers the chance of exposure around feed areas, bedding, lambing spaces, and shared handling equipment.
There is no therapy that reverses scrapie, so affected animals are often humanely euthanized to limit spread and prevent prolonged suffering. This is especially important when animals have severe itching, poor balance, weight loss, or trouble standing.
Veterinary testing and official reporting help confirm whether scrapie is present in the flock. Not every approach works the same way, so the exact plan depends on local rules, the species involved, and whether other animals may have been exposed.
In sheep, breeding for genetic resistance can lower flock risk over time. This does not treat an animal that already has scrapie, but it can be an important long-term control step.
Your genes may have an impact on how drugs work for you
For scrapie, this topic is limited because there are no standard medicines that treat the disease itself, so there is no well-established genetic testing used to guide drug choice or dosing. In animals affected by scrapie, genes are better known for changing the chance of getting the disease rather than changing how medicines work. If supportive medicines are used for comfort or general care, response can still vary from one animal to another, but this is not a well-established part of scrapie care.
Pharmacological treatments
Scrapie has no approved medicine that can cure it, slow it down, or clear the infection. This means there is currently no effective treatment for scrapie in sheep or goats once signs begin. Finding the right medication can be a process of trial, patience, and adjustment, but with scrapie, drug treatment has not been shown to change the course of disease. In practice, care is usually focused on comfort, safety, and flock management rather than long-term drug therapy.
There are no licensed drugs for scrapie, and no medicine is known to stop the abnormal prion protein that causes it. Because scrapie is progressive and fatal, treatment is not aimed at cure.
A veterinarian may sometimes use medicines such as sedatives or pain-relieving drugs to reduce distress, restlessness, or injury risk in an affected animal. These medicines do not treat scrapie itself and are used only for short-term supportive care when appropriate.
Many animals with scrapie continue to worsen despite supportive medicines, with problems such as itching, tremors, poor balance, and weight loss. For this reason, humane euthanasia and disease-control measures are often recommended instead of ongoing drug treatment.
Genetic influences
For flock owners, scrapie can seem to affect some family lines more than others, even when animals share the same pasture and feed. Much of this difference comes from changes in the prion protein gene, called PRNP: in sheep, some versions greatly raise the chance of classical scrapie, while others make it less likely, and similar gene effects are also seen in goats. These gene differences can also influence how long it takes signs to appear after exposure. Having a genetic risk is not the same as having the disease itself, because scrapie also depends on exposure to abnormal prion protein and on the type of scrapie involved. In practical terms, the genetic risk of scrapie in sheep is strong enough that breeding programs in some countries select for more resistant animals. Even so, genetics does not give complete protection in every setting, and the pattern can differ between classical and atypical scrapie.
Is Scrapie genetic?
Genetics matter a lot in scrapie: variants in the PRNP gene strongly affect an animal's risk, and selective breeding can lower the chance of disease in sheep flocks. Genetics is only part of the picture, because exposure also matters.
Having a genetic risk is not necessarily a diagnosis
Genetic variants are a usual part of human biology and are seen often in the general population. Most do not have a direct effect on health and simply reflect natural differences among people. For many genes, having a variant connected to a condition suggests a possible link rather than a certain diagnosis, especially when several genes and environmental factors are involved. In some situations, though, a single well-understood variant in a particular gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For owners wondering about treatment options for Scrapie, there is currently no medicine proven to cure it or reliably slow it down. That means genetics does not usually help doctors or veterinarians choose a drug for Scrapie the way it can for some other conditions; instead, it is used mainly to estimate risk. In sheep, changes in the prion protein gene can make some animals much less likely to develop Scrapie, so genetic testing for Scrapie risk may help guide breeding and flock management. In goats, genetic differences may also affect risk, but the evidence is less consistent, so testing is used more selectively. Genetics is only one factor, and because Scrapie is managed mostly through prevention, monitoring, and disease-control programs rather than medication, the main value of genetic information is lowering future cases, not tailoring a treatment.
Interactions with other conditions
In animals with scrapie, the main issue is usually not that it directly causes other diseases, but that its symptoms can overlap with several other conditions and make diagnosis harder. Early symptoms of scrapie, such as itching, behavior changes, weight loss, and trouble walking, can look similar to problems caused by parasites, skin disease, mineral deficiencies, or other brain and nerve illnesses. Doctors call it a “comorbidity” when two conditions occur together, and in a sheep or goat that already has another illness, those signs may seem worse or more confusing. This matters because an animal with scrapie can also have routine health problems at the same time, which may delay recognition of what is really going on. Scrapie is not known to spread to people, but it is important to separate it from other animal diseases that may need different treatment or public health action.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Scrapie?
In sheep and goats, scrapie can be confused with skin problems such as lice or mites, which can also cause intense itching and rubbing, and with other illnesses that affect the brain or nerves, such as listeriosis, rabies, or severe illness late in pregnancy. These conditions can also lead to weight loss, tremors, behavior changes, or trouble walking, so a veterinarian usually needs testing to tell them apart.
History
Long before modern lab testing, farmers in Europe were already noticing a troubling pattern in some flocks: sheep would rub hard against fences or posts, seem unusually restless, and gradually lose condition. That repeated scraping behavior is where scrapie got its name. Historical accounts go back several centuries, with written descriptions becoming clearer in the 1700s, especially in sheep-raising regions.
At first, scrapie was understood only through what people could see day to day. A shepherd might notice an animal that seemed off balance, overly itchy, or slower to keep up with the flock, and over time these signs were recognized as part of the same illness. Because the disease develops slowly, early descriptions were often incomplete, and it took years before veterinarians realized they were dealing with a distinct condition rather than several unrelated problems.
As medical science evolved, researchers began to separate scrapie from other illnesses that can affect the brain and nerves. By the 19th and early 20th centuries, veterinary reports had described a more consistent picture of the disease, including changes in behavior, movement, and body condition. This helped establish scrapie as a long-standing disease of sheep and goats rather than a new outbreak.
A major turning point came in the 20th century, when experiments showed that scrapie could be passed from affected animals to healthy ones under certain conditions. That finding changed how scientists thought about the disease. It was no longer seen as simply a random problem within a flock, but as a condition with a specific biological cause that could spread in ways researchers needed to understand more clearly.
Later research showed that scrapie belongs to a group of rare brain diseases caused by abnormal proteins, now known as prion diseases. That discovery shaped modern veterinary medicine and also influenced the study of related animal and human disorders. Although scrapie had been recognized for a very long time, these newer findings explained why the illness behaves differently from ordinary infections caused by bacteria or viruses.
Today, the history of scrapie still matters. It helps explain why monitoring, breeding programs, and flock health rules became such an important part of control efforts in many countries. Knowing this background also makes it easier to understand why early symptoms of scrapie can be subtle at first, even though the disease itself has been observed for generations.