Scrapie disease in goats is a fatal, untreatable neurological condition caused by abnormal proteins called prions. Key signs include intense itching, coordination loss, and weight loss. It spreads through birth fluids and contact. Control involves strict biosecurity, genetic testing for resistance, and participation in eradication programs like the USDA’s National Scrapie Eradication Program. Early detection and herd management are crucial to protect your animals.

Finding out your goat might have a serious illness can be very worrying. Scrapie, a disease affecting goats and sheep, is particularly concerning because it’s always fatal and has no cure. It can be frustrating to deal with a condition that seems mysterious and difficult to prevent. Many goat owners wonder how to spot it, what causes it, and most importantly, how to keep their beloved animals safe. You’re in the right place to get clear, practical answers. We’ll walk through everything you need to know about Scrapie, from recognizing its subtle signs to implementing effective control measures, helping you protect your herd with confidence.

Scrapie Disease in Goats: Signs, Causes, and How to Control It

What is Scrapie Disease?

Scrapie is a progressive, fatal disease of the nervous system that affects sheep and goats. It belongs to a group of diseases known as Transmissible Spongiform Encephalopathies (TSEs), which also includes Bovine Spongiform Encephalopathy (BSE, or “mad cow disease”) in cattle and Creutzfeldt-Jakob disease (CJD) in humans. The name “scrapie” comes from one of the most common symptoms: affected animals often scrape off their wool or hair due to intense itching.

Unlike diseases caused by bacteria or viruses, Scrapie is caused by an abnormal form of a normal protein called a prion. These misfolded prions accumulate in the brain and other tissues, leading to brain damage and neurological dysfunction. The disease has a very long incubation period, often taking several years (typically 2 to 5 years, but sometimes longer) from the time of infection until clinical signs appear. This long delay makes it particularly challenging to identify and control.

Understanding the Prion: The Cause of Scrapie

The core cause of Scrapie is a unique infectious agent: the prion. Prions are not living organisms like bacteria or viruses; they are simply misfolded versions of a normal protein found in the brain and other tissues of mammals, called PrP^C (cellular prion protein). For reasons not fully understood, this normal protein can spontaneously or, more commonly, through contact with an abnormal prion, change its shape into a disease-causing form, PrP^Sc (scrapie prion protein).

Once a single PrP^Sc prion is present, it acts as a template, forcing other normal PrP^C proteins to misfold into the abnormal, infectious form. These abnormal prions are highly resistant to degradation by enzymes, heat, and common disinfectants, making them incredibly persistent in the environment. They accumulate in the brain, forming microscopic holes that give the brain a “spongy” appearance under a microscope, hence the term “spongiform encephalopathy.” This accumulation disrupts normal brain function, leading to the severe neurological symptoms characteristic of Scrapie.

The genetic makeup of a goat can influence its susceptibility to Scrapie. Specific variations (polymorphisms) in the gene that codes for the prion protein can make an animal more or less resistant to the disease. This genetic component is a crucial aspect of Scrapie control strategies.

How Scrapie Spreads in Goats

Scrapie is primarily transmitted from an infected mother to her offspring, or to other animals, during or shortly after the birthing process. The placenta and birth fluids from an infected doe contain high concentrations of the Scrapie prion. When these contaminated materials are shed into the environment, they can infect other susceptible animals that ingest them. This is the most common route of transmission, making lambing and kidding pens high-risk areas.

Key transmission routes include:

• Mother-to-Offspring (Vertical Transmission): Prions are shed in the placenta and birth fluids of infected does. Newborn kids, as well as other susceptible animals in the same birthing environment, can become infected by ingesting these contaminated materials.
• Environmental Contamination: Prions are incredibly resilient and can persist in the soil and on surfaces for years. Pastures, barns, and equipment previously used by infected animals can remain infectious, posing a risk to new, uninfected animals.
• Animal-to-Animal (Horizontal Transmission): While less common than environmental transmission, direct contact between infected and susceptible animals, particularly through shared feed or water sources contaminated with saliva or feces, can potentially transmit the disease. However, the primary risk remains environmental contamination from birth tissues.
• Genetic Susceptibility: While not a transmission route itself, an animal’s genetic makeup plays a significant role in its susceptibility to infection and how quickly the disease progresses once infected. Animals with certain genetic profiles are more likely to contract Scrapie if exposed.

The long incubation period means that an infected goat can appear perfectly healthy for years while shedding prions and potentially infecting others, making the disease insidious and challenging to eradicate.

Signs and Symptoms of Scrapie in Goats

Recognizing the signs of Scrapie in goats can be challenging because they often develop slowly and can be mistaken for other conditions or simply old age. The clinical signs typically appear in adult goats, usually between 2 and 5 years of age, though they can manifest earlier or later. As the disease progresses, the symptoms become more pronounced and debilitating.

Symptoms can be broadly categorized into behavioral, neurological, and physical changes:

Behavioral Changes:

• Intense Itching and Rubbing: This is one of the hallmark signs, giving the disease its name. Goats will rub and scrape themselves against fences, posts, or anything available, often leading to patches of wool or hair loss, skin abrasions, and sores. They may also bite or nibble at their flanks, legs, or tail.
• Increased Nervousness or Excitability: Affected goats may become unusually apprehensive, jumpy, or easily startled. They might show an exaggerated response to sudden noises or movements.
• Behavioral Changes: This can include listlessness, depression, or a change in normal flock behavior, such as separating from the herd.
• Head Pressing: Leaning or pressing their head against a wall or fence.

Neurological Signs:

• Loss of Coordination (Ataxia): This is a progressive symptom. Early signs might include subtle unsteadiness, especially when turning or going up or down slopes. As the disease advances, goats may develop a high-stepping gait (trotting with exaggerated leg movements), stumbling, or an inability to stand.
• Tremors: Fine muscle tremors, particularly noticeable in the head and neck, can occur.
• Abnormal Gaits: Besides ataxia, goats may show an unusual wide-based stance or a tendency to fall.
• Blindness: In some advanced cases, goats may become blind.
• Inability to Stand: In the final stages, affected goats become recumbent (lie down and cannot get up) and eventually die.

Physical Changes:

• Weight Loss: Despite maintaining a good appetite, goats with Scrapie often progressively lose weight and become emaciated.
• Poor Coat Condition: Related to the itching and rubbing, the coat may appear rough, matted, or have bald patches.
• Grinding Teeth: A sign of discomfort or pain.
• Excessive Thirst and Urination: While not as common, some animals may exhibit polydipsia (excessive thirst) and polyuria (excessive urination).

It’s important to note that not all goats will show every symptom, and the progression can vary. If you observe any combination of these signs, especially in an adult goat, Scrapie should be considered a possibility, and veterinary consultation is essential.

Table 1: Common Scrapie Symptoms in Goats

Symptom Category	Specific Signs	Description/Impact
Behavioral	Intense Itching/Rubbing	Goat scratches vigorously against objects, bites at flanks; leads to hair loss, skin lesions.
	Nervousness/Excitability	Startles easily, appears anxious, may separate from herd.
	Head Pressing	Repeatedly presses head against walls or fences.
Neurological	Ataxia (Loss of Coordination)	Unsteady gait, stumbling, high-stepping walk, difficulty turning or standing.
	Tremors	Fine muscle tremors, especially in the head and neck.
	Blindness	Progressive loss of vision in advanced stages.
Physical	Progressive Weight Loss	Goat becomes emaciated despite maintaining appetite.
	Poor Coat Condition	Rough, matted, or patchy coat due to rubbing.
	Recumbency	Inability to stand up in final stages, leading to death.

Diagnosing Scrapie: Challenges and Methods

Diagnosing Scrapie can be challenging, primarily due to its long incubation period and the non-specific nature of early clinical signs. Many symptoms can mimic other conditions, such as internal parasites, nutritional deficiencies, or other neurological disorders. Definitive diagnosis often requires laboratory testing, typically after the animal has died.

Challenges in Diagnosis:

• Long Incubation Period: Goats can be infected for years without showing any signs, making early detection difficult.
• Non-Specific Clinical Signs: Early symptoms like itching or weight loss can be caused by many other common goat ailments.
• No Live Animal Test for Early Stages: While some live animal tests exist, they are often only effective in the later stages of the disease or require specific tissue samples that are not always easy to obtain.

Diagnostic Methods:

The most reliable methods for diagnosing Scrapie involve examining tissue samples for the presence of the abnormal prion protein.

• Post-Mortem Examination (Brain Tissue): The gold standard for definitive diagnosis is the examination of brain tissue collected after the animal has died. A veterinarian or state diagnostic laboratory can perform a histopathological examination to look for the characteristic spongiform changes in the brain and use immunohistochemistry (IHC) or Western blot tests to detect the abnormal prion protein.
• Live Animal Testing (Rectal Biopsy): For live animals, the most common test involves taking a biopsy from the lymphoid tissue in the rectum. This test is highly accurate in genetically susceptible animals showing clinical signs. However, it may not detect the disease in all infected animals, especially in early stages or in animals with certain genetic types. Research continues to improve the sensitivity and accessibility of live animal tests.
• Third Eyelid Biopsy: In some cases, a biopsy of the lymphoid tissue in the third eyelid (nictitating membrane) can also be used, though this is less common than rectal biopsy.
• Genetic Testing: While not a diagnostic test for the presence of the disease itself, genetic testing can determine a goat’s susceptibility to Scrapie. By analyzing specific codons (e.g., 171 and 136) in the prion protein gene, breeders can identify animals that are more resistant or more susceptible. This information is invaluable for breeding programs aimed at increasing Scrapie resistance in a herd.

If Scrapie is suspected, it is crucial to contact your veterinarian immediately. They can collect appropriate samples and send them to a certified diagnostic laboratory. Reporting suspected cases is mandatory in many regions to facilitate disease surveillance and control efforts.

The Impact of Scrapie on Goat Herds and the Industry

Scrapie poses a significant threat to individual goat herds and the wider small ruminant industry. Its long incubation period and insidious nature mean that by the time clinical signs appear, the disease may have already spread silently within a flock for years, affecting multiple generations.

The impacts include:

• Economic Losses:
  • Animal Deaths: Scrapie is always fatal, leading to direct loss of valuable breeding stock and production animals.
  • Reduced Productivity: Even before death, affected animals may suffer from weight loss and decreased productivity.
  • Slaughter and Depopulation: In some cases, entire infected herds or flocks may need to be depopulated to eradicate the disease, leading to devastating financial losses for producers.
  • Trade Restrictions: Countries free of Scrapie may impose trade barriers on live animals, genetic material, or even products from countries or regions where Scrapie is present, impacting international markets.
• Erosion of Genetic Progress: The need to cull valuable bloodlines due to Scrapie infection can set back years of genetic improvement efforts in a herd.
• Reputational Damage: A farm or breeder found to have Scrapie can suffer significant reputational damage, making it difficult to sell animals or products.
• Public Health Concerns (Indirect): While Scrapie is not known to directly transmit to humans, it is a TSE, and the general public and regulatory bodies are cautious about any disease in this family due to the historical link between BSE and vCJD in humans. This caution can lead to stricter regulations and consumer apprehension, even if the risk is theoretical for Scrapie in goats.
• Increased Management Burden: Implementing and maintaining strict biosecurity measures, genetic testing, and participating in eradication programs require significant time, effort, and resources from producers.

Ultimately, Scrapie undermines herd health, profitability, and the long-term sustainability of the goat industry. This is why robust control and eradication programs are so vital.

Prevention and Control Strategies for Scrapie

Controlling and eventually eradicating Scrapie requires a multi-faceted approach focusing on prevention, early detection, and strict management of infected herds. Because there is no treatment or vaccine, the emphasis is entirely on preventing the spread of the prion.

1. Genetic Resistance and Breeding Programs

One of the most powerful tools in Scrapie control is selective breeding for genetic resistance. Goats, like sheep, have a gene that codes for the prion protein, and variations (polymorphisms) in this gene can influence an animal’s susceptibility to Scrapie. In goats, specific codons (parts of the gene) are of interest, though the genetic markers for resistance are not as clearly defined or widely utilized as in sheep.

• Testing for Susceptibility: Producers can submit blood or tissue samples for genetic testing to determine their goats’ prion protein genotype. While no goat genotype offers complete immunity, some are significantly more resistant to Scrapie than others.
• Selective Breeding: By identifying and breeding from goats with more resistant genotypes, producers can gradually increase the overall genetic resistance of their herd over generations. This reduces the likelihood of an animal developing the disease even if exposed.
• Understanding Goat Genetics: Research is ongoing to better understand the specific genetic markers for Scrapie resistance in various goat breeds. Consult with your veterinarian or genetic experts for the latest information relevant to your herd.

2. Biosecurity Measures

Strict biosecurity is paramount to prevent the introduction and spread of Scrapie, especially given the prion’s environmental persistence.

• Closed Herds: The safest approach is to maintain a closed herd, meaning no new animals are introduced from outside sources. If new animals must be brought in, source them only from flocks or herds that are certified Scrapie-free or participate in a Scrapie flock certification program.
• Quarantine New Animals: Any new goat introduced to the herd should undergo a strict quarantine period (at least 30 days) away from the main herd. During this time, monitor for any signs of illness and consider genetic testing for Scrapie susceptibility.
• Control Breeding Practices: Avoid shared breeding bucks or does with unknown health status. If artificial insemination (AI) or embryo transfer (ET) is used, ensure the source animals are from Scrapie-free flocks.
• Clean Birthing Environment: Since birth fluids and placentas are primary sources of infection, ensure kidding pens are thoroughly cleaned and disinfected between uses. Remove and properly dispose of all birth tissues, afterbirth, and dead newborns immediately. Do not allow other animals to access these materials.
• Separate Youngstock: Consider raising young kids separately from adult animals, especially if the Scrapie status of the adult herd is uncertain, to minimize exposure risk.
• Control Access: Limit access by visitors, vehicles, and equipment from other farms. If external equipment is used, ensure it is thoroughly cleaned and disinfected before entering your premises.
• Carcass Disposal: Proper disposal of dead animals is crucial. Carcasses should be promptly removed and disposed of according to local regulations (e.g., incineration, rendering, burial) to prevent environmental contamination.

3. National Scrapie Eradication Program (NSEP)

In the United States, the USDA’s Animal and Plant Health Inspection Service (APHIS) manages the National Scrapie Eradication Program (NSEP). This program aims to eliminate Scrapie from the U.S. sheep and goat population.

• Official Identification: All sheep and goats, with some exceptions, must have official individual identification (e.g., ear tags) when moved interstate or for certain other activities. This allows for traceback of animals to their flock of origin if a Scrapie case is identified.
• Flock/Herd Plans: When Scrapie is diagnosed in a herd, a flock plan is developed with state and federal animal health officials. This plan outlines specific actions to eradicate the disease from the affected premises, which may include culling infected animals, enhanced surveillance, genetic testing, and specific management practices.
• Voluntary Scrapie Flock Certification Program (SFCP): This program allows producers to demonstrate their flock’s Scrapie-free status through a rigorous surveillance and testing protocol. Participation enhances marketability and provides a higher level of assurance for buyers.
• Surveillance and Reporting: The NSEP relies on active surveillance, including testing of animals submitted to slaughter or diagnostic laboratories. It is mandatory to report any suspected cases of Scrapie to state or federal animal health authorities.

4. Management of Infected Herds

If Scrapie is diagnosed in your herd, immediate action is required, often in conjunction with regulatory authorities:

• Isolation: Isolate affected or suspected animals immediately to prevent further spread.
• Depopulation (in severe cases): In some instances, particularly with widespread infection or highly susceptible genotypes, complete depopulation of the herd followed by thorough cleaning and disinfection of premises may be recommended or required.
• Targeted Culling: In less severe cases, or as part of a flock plan, specific animals (e.g., all progeny of an infected dam, or genetically susceptible animals) may be culled.
• Intensified Biosecurity: All biosecurity measures must be rigorously enforced.
• Environmental Decontamination: While prions are notoriously resistant, efforts should be made to clean and disinfect facilities where infected animals were housed, especially birthing areas. High-pressure washing, followed by the application of strong disinfectants (e.g., bleach solutions, though efficacy against prions varies), and prolonged fallow periods can help reduce environmental contamination.

5. Disinfection Protocols

Traditional disinfectants are often ineffective against prions. However, certain protocols can reduce prion contamination in the environment:

• Physical Removal: Thoroughly remove all organic matter (feces, bedding, feed, tissues) from surfaces.
• High-Pressure Washing: Use high-pressure water to clean surfaces.
• Chemical Treatments: Strong solutions of sodium hypochlorite (bleach, 2% available chlorine) or sodium hydroxide (lye, 2M) applied for extended periods (hours) have shown some efficacy against prions. Consult with veterinary authorities for specific recommendations.
• Heat Treatment: Incineration is the most effective way to destroy prions in carcasses and contaminated materials.

Living with Scrapie: Management and Ethical Considerations

For producers who find Scrapie in their herd, the emotional and financial toll can be immense. Beyond the practical control measures, there are significant ethical considerations and long-term management challenges.

Managing a Scrapie-affected herd involves a commitment to strict protocols, which can include:

• Continuous Surveillance: Even after initial control measures, ongoing vigilance for signs of the disease and regular testing are crucial.
• Record Keeping: Meticulous records of animal identification, movements, breeding, and health status are essential for traceback and program compliance.
• Breeding for Resistance: A long-term strategy should involve gradually shifting the herd’s genetic profile towards greater Scrapie resistance, which can take multiple generations.
• Community Responsibility: Producers have a responsibility to prevent the spread of Scrapie to other herds. This means transparent communication with buyers and adherence to all regulatory requirements.

The decision to depopulate a herd versus managing it through a flock plan is often difficult, balancing economic viability, animal welfare, and the broader goal of disease eradication. Support from veterinarians, state animal health officials, and producer organizations can be invaluable during such challenging times.

Reporting Suspected Cases: Why it’s Crucial

Reporting suspected cases of Scrapie is not just a regulatory requirement; it is a critical step in protecting the entire goat and sheep industry. Scrapie is a “reportable disease” in many countries, meaning that veterinarians and livestock owners are legally obligated to inform animal health authorities if they suspect an animal has the disease.

Why is reporting so important?

• Disease Surveillance: Reporting allows animal health authorities to track the prevalence and distribution of Scrapie, identify affected areas, and assess the effectiveness of eradication programs.
• Preventing Further Spread: Early reporting enables officials to investigate the source of infection, implement control measures, and prevent the disease from spreading to other farms or regions.
• Protecting Trade: A country’s Scrapie status affects its ability to trade live animals and animal products internationally. Robust surveillance and reporting demonstrate a commitment to disease control, which helps maintain market access.
• Supporting Research: Reported cases contribute valuable data for ongoing research into Scrapie, leading to better diagnostic tools, control strategies, and a deeper understanding of the disease.

If you suspect Scrapie in your goat, contact your local veterinarian or state animal health official immediately. They will guide you through the necessary steps for diagnosis and management.

Future Directions in Scrapie Research and Control

While significant progress has been made in understanding and controlling Scrapie, research continues to explore new avenues for more effective prevention and eradication.

• Improved Live Animal Diagnostics: Scientists are working to develop more sensitive and reliable live animal tests that can detect Scrapie earlier in the incubation period, making control efforts more proactive.
• Advanced Genetic Understanding: Further research into the genetic basis of Scrapie resistance in different goat breeds could lead to more precise breeding strategies and the identification of new resistant genotypes.
• Environmental Decontamination: New methods for decontaminating premises and pastures contaminated with prions are being investigated, as current methods are often challenging and not entirely effective.
• Vaccine Development (Long-term): While highly challenging due to the nature of prions, research into potential therapeutic or prophylactic approaches, including vaccines, is an ongoing, long-term goal.
• Epidemiological Studies: Continued study of how Scrapie spreads in different environments and management systems can refine biosecurity protocols and target control efforts more effectively.

These ongoing efforts highlight the commitment of the scientific and veterinary communities to ultimately eradicate Scrapie and safeguard the health of small ruminant populations worldwide.

Table 2: Key Scrapie Control Measures & Their Benefits

Control Measure	Primary Action	Key Benefits
Genetic Resistance Breeding	Test and select goats with resistant prion protein genotypes.	Increases herd’s natural resistance; reduces susceptibility to infection.
Strict Biosecurity	Closed herds, quarantine new animals, proper disposal of birth tissues.	Prevents introduction of prions; minimizes environmental contamination.
National Eradication Programs	Official ID, flock plans, mandatory reporting, surveillance.	Provides systematic framework for disease elimination; supports traceback.
Proper Carcass Disposal	Incineration, rendering, or burial of dead animals.	Prevents environmental spread of highly resistant prions.
Clean Birthing Areas	Thorough cleaning and disinfection of kidding pens after use.	Reduces primary route of transmission (mother-to-offspring/environment).

Frequently Asked Questions (FAQ)

Q1: Can humans get Scrapie from goats?

A1: There is currently no scientific evidence that Scrapie can be transmitted to humans. Scrapie is a distinct animal disease, and extensive research has not found a link between Scrapie in sheep or goats and any human prion disease, including variant Creutzfeldt-Jakob disease (vCJD), which was linked to Bovine Spongiform Encephalopathy (BSE) in cattle. However, out of an abundance of caution, it’s always wise to practice good hygiene when handling any livestock.

Q2: Is there a cure or vaccine for Scrapie in goats?

A2: Unfortunately, there is no cure or vaccine for Scrapie. Once a goat shows clinical signs, the disease is always fatal. This is why control efforts focus entirely on prevention, early detection, and eradication through management and genetic selection rather than treatment.

Q3: How long can a goat live with Scrapie?

A3: The incubation period for Scrapie is very long, typically 2 to 5 years, but can range from 1 to 8 years or more, meaning a goat can be infected for a long time before showing any symptoms. Once clinical signs appear, the disease progresses over weeks to several months, leading to death. The animal’s quality of life deteriorates significantly during this symptomatic phase.

Q4: Can I test my goats for Scrapie while they are alive?

A4: Yes, live animal tests are available, primarily through rectal biopsy. This test detects the abnormal prion protein in lymphoid tissues. While it is a valuable tool, it may not detect the disease in all infected animals, especially in the very early stages of infection or in goats with certain genetic types. Genetic testing is also available to determine a goat’s susceptibility to Scrapie, which is different from testing for active infection.

Q5: What should I do if I suspect my goat has Scrapie?

A5: If you suspect your goat has Scrapie, you should immediately contact your veterinarian. Scrapie is a reportable disease, meaning it is legally required to inform animal health authorities. Your veterinarian will help you collect appropriate samples for diagnosis and guide you on the necessary steps, which may involve state or federal animal health officials.

Q6: Can Scrapie be completely eliminated from a farm?

A6: Yes, it is possible to eliminate Scrapie from a farm, but it requires rigorous and sustained effort. This often involves implementing a comprehensive flock plan in cooperation with animal health authorities, which may include culling infected and exposed animals, strict biosecurity measures, thorough cleaning and disinfection of premises, and a long-term commitment to breeding for genetic resistance. The resilience of the prion in the environment means the process can be lengthy and challenging.

Q7: Does Scrapie affect all goat breeds equally?

A7: While all goat breeds can be susceptible to Scrapie, there can be differences in genetic susceptibility. Research into specific prion protein gene variations (polymorphisms) is ongoing to better understand breed-specific resistance and susceptibility. Some breeds or individual animals within breeds may carry genetic markers that make them more or less likely to develop the disease if exposed.

Conclusion

Scrapie disease in goats presents a significant challenge for producers, but it is a manageable one with the right knowledge and proactive strategies. Understanding the signs—from intense itching and coordination loss to behavioral changes—is the first crucial step. Recognizing that the disease is caused by persistent prions and primarily spreads through contaminated birth fluids emphasizes the importance of strict biosecurity and proper disposal of birth materials. By leveraging genetic testing to breed for resistance, diligently practicing biosecurity, and participating in national eradication programs, goat owners can significantly reduce the risk and impact of Scrapie. While there’s no cure, a committed, multi-faceted approach ensures the health and longevity of your herd, protecting your animals and the wider industry.