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Mad cow cause. Mad Cow Disease: Symptoms, Causes, and Treatments for vCJD

What is mad cow disease and how does it affect humans. Can mad cow disease be transmitted through food. What are the symptoms of variant Creutzfeldt-Jakob disease. How is mad cow disease prevented in the food supply.

Understanding Mad Cow Disease and Its Human Impact

Mad cow disease, scientifically known as bovine spongiform encephalopathy (BSE), is a progressive and fatal neurological disorder affecting adult cattle. This condition has garnered significant attention due to its potential impact on human health through a variant form known as Creutzfeldt-Jakob disease (vCJD). To comprehend the complexities of this disease, it’s crucial to explore its origins, transmission, and implications for both animal and human populations.

The Prion Culprit: Unraveling the Cause of Mad Cow Disease

At the heart of mad cow disease lies an abnormal protein called a prion. Unlike typical infectious agents such as bacteria or viruses, prions are misfolded proteins that can trigger a cascade of neurological damage. These prions primarily target the central nervous system, leading to the deterioration of brain and spinal cord tissue. The exact mechanism by which normal proteins transform into these destructive prions remains a subject of ongoing research, highlighting the enigmatic nature of this disease.

From Cattle to Humans: The vCJD Connection

The human variant of mad cow disease, vCJD, is believed to result from consuming beef products contaminated with infected central nervous system tissue. This link between bovine BSE and human vCJD underscores the critical importance of stringent food safety measures. The U.S. Department of Agriculture (USDA) has implemented rigorous testing protocols, examining hundreds of thousands of cattle for BSE to safeguard public health.

Recognizing the Symptoms of Variant Creutzfeldt-Jakob Disease

Identifying vCJD in its early stages can be challenging due to its nonspecific initial symptoms. As the disease progresses, patients may experience a range of neurological and cognitive disturbances.

  • Early symptoms: Depression and loss of coordination
  • Later stages: Development of dementia
  • Advanced stages: Detectable brain abnormalities via MRI

The insidious nature of vCJD lies in its ability to affect individuals of all age groups, with symptoms typically manifesting in younger patients compared to classic CJD. Tragically, vCJD is invariably fatal, with most patients succumbing to the disease within 13 months of symptom onset.

Differentiating vCJD from Classic CJD

It’s crucial to distinguish variant CJD from its sporadic counterpart, classic CJD. While both forms are fatal prion diseases, they differ in their origins and demographic impacts:

  • Classic CJD: No known cause, affects 1-2 per million annually worldwide
  • Variant CJD: Linked to BSE exposure, primarily affects younger individuals

This distinction is vital for accurate diagnosis and epidemiological tracking, as classic CJD occurs even in regions without reported cases of mad cow disease.

Preventive Measures: Safeguarding the Food Supply

In response to the threat of mad cow disease, governmental agencies have implemented comprehensive preventive strategies to protect consumers and maintain the integrity of the food supply.

USDA Regulations and Import Restrictions

Since 1989, the U.S. government has enforced strict import bans on live animals and certain meat products from countries with known BSE cases. This proactive approach aims to prevent the entry of potentially infected materials into the American food chain.

Removal of High-Risk Tissues

A critical preventive measure involves the mandatory removal of brain and spinal cord materials from high-risk cattle. This includes older animals, those unable to walk, and any showing signs of neurological problems. By eliminating these tissues from the food supply, the risk of prion transmission to humans is significantly reduced.

The Safety of Milk and Dairy Products

Concerns about mad cow disease naturally extend to all bovine products, including milk. However, extensive research has provided reassuring evidence regarding the safety of dairy consumption.

Scientific Findings on Milk Safety

Experimental studies have consistently shown that milk from BSE-infected cows does not transmit the infection. This crucial finding has alleviated concerns about the potential risk associated with milk and dairy product consumption.

FDA Regulations on Bovine-Derived Ingredients

The Food and Drug Administration (FDA) has taken additional precautions by restricting the importation of cosmetic and dietary supplement ingredients containing bovine materials from at-risk countries. This comprehensive approach ensures that even non-food products derived from cattle are subject to stringent safety measures.

Global Perspective: Mad Cow Disease Across Borders

While the United States has implemented robust measures to prevent BSE, the global nature of the food supply necessitates an understanding of the international landscape.

Historical Context and Peak Incidence

Mad cow disease first came to prominence in 1986 when it was reported in cattle in the United Kingdom. The epidemic reached its zenith in January 1993, with nearly 1,000 new cases identified weekly. This alarming spread prompted intensified research and preventive efforts worldwide.

Countries Affected by BSE

Beyond the UK, several European countries have reported cases of BSE in native-born cattle, including:

  • Austria
  • Belgium
  • Czech Republic
  • Denmark
  • Finland
  • France
  • Germany
  • Italy
  • Ireland
  • Luxembourg
  • Liechtenstein
  • Netherlands
  • Poland
  • Portugal
  • Slovakia
  • Slovenia
  • Spain
  • Switzerland

This widespread occurrence underscores the importance of international cooperation in monitoring and controlling the spread of BSE.

Assessing the Risk for Travelers

For Americans traveling abroad, concerns about exposure to vCJD through food consumption are natural. The Centers for Disease Control and Prevention (CDC) provides guidance on this matter, emphasizing the nuanced nature of risk assessment.

CDC Risk Assessment

According to the CDC, the current risk of acquiring vCJD from any specific country is considered extremely small. However, the interconnected global food supply chain makes precise risk determination challenging, as cattle products from one nation may be distributed and consumed in others.

Precautionary Measures for Travelers

While the risk is low, travelers to countries with a history of BSE may consider taking additional precautions:

  • Avoiding beef and beef products in high-risk areas
  • Opting for alternative protein sources
  • Staying informed about local food safety practices

These measures, while not officially mandated, can provide an extra layer of reassurance for concerned individuals.

The Future of Mad Cow Disease Research and Prevention

As our understanding of prion diseases evolves, so too do the strategies for combating mad cow disease and its human variant. Ongoing research focuses on several key areas that promise to enhance our ability to detect, prevent, and potentially treat these devastating conditions.

Advances in Diagnostic Techniques

One of the most significant challenges in managing vCJD has been the difficulty of early diagnosis. Current research is exploring innovative diagnostic methods, including:

  • More sensitive brain imaging techniques
  • Blood-based biomarker tests
  • Advanced prion detection methods in tissue samples

These developments could lead to earlier intervention and improved patient care, as well as more effective surveillance of both animal and human populations.

Emerging Therapeutic Approaches

While vCJD remains invariably fatal, scientists are investigating potential treatment strategies that could slow or halt disease progression. Some promising avenues include:

  • Antibody therapies targeting prion proteins
  • Small molecule compounds to prevent prion aggregation
  • Gene therapy approaches to modulate prion protein expression

Although a cure remains elusive, these research directions offer hope for future therapeutic interventions.

Enhanced Surveillance and Prevention Strategies

The global effort to prevent the spread of BSE and vCJD continues to evolve. Future initiatives may include:

  • More comprehensive international tracking of cattle movements
  • Advanced genetic testing to identify BSE-resistant cattle breeds
  • Improved methods for decontaminating prion-infected environments

These measures aim to further reduce the already low risk of BSE transmission to humans and maintain the safety of the global food supply.

Public Health Implications and Consumer Awareness

The story of mad cow disease and vCJD serves as a powerful reminder of the intricate connections between animal health, food safety, and human well-being. As we continue to navigate these complex issues, public awareness and education play crucial roles in maintaining a safe and informed society.

The Role of Consumer Education

Empowering consumers with accurate information about mad cow disease and food safety is essential. Key areas of focus include:

  • Understanding the real risks associated with beef consumption
  • Recognizing the extensive safety measures in place
  • Making informed choices about food purchases and preparation

By fostering a well-informed public, we can help mitigate unfounded fears while promoting responsible consumer behavior.

The Importance of Continued Vigilance

Despite the relatively low current risk of vCJD, the lessons learned from the mad cow disease crisis underscore the need for ongoing vigilance in food safety and public health. This includes:

  • Maintaining robust testing and surveillance programs
  • Adapting regulations to reflect new scientific findings
  • Fostering international cooperation in disease monitoring and prevention

By remaining proactive and responsive to emerging threats, we can better protect both animal and human populations from the devastating effects of prion diseases.

Balancing Precaution and Progress

As we move forward, it’s crucial to strike a balance between necessary precautions and the advancement of scientific understanding. This involves:

  • Supporting continued research into prion diseases
  • Evaluating and refining existing safety measures
  • Encouraging innovation in food production and safety technologies

By embracing a dynamic approach to mad cow disease and vCJD, we can ensure that our response remains both effective and proportionate to the evolving nature of these challenges.

In conclusion, while mad cow disease and vCJD have left an indelible mark on our collective consciousness, the concerted efforts of scientists, regulators, and industry professionals have significantly mitigated the risks associated with these conditions. As we look to the future, ongoing research, vigilant monitoring, and public education will remain key pillars in our defense against these rare but serious threats to animal and human health.

Symptoms, Causes and Treatments for vCJD

Written by Michael W. Smith, MD

  • Mad cow disease has hit the U.S. and questions about this mysterious disease abound. Here’s what you need to know about mad cow disease.
  • What Is Mad Cow Disease?
  • Does Cooking Food Kill the Prion That Causes Mad Cow Disease?
  • Does Mad Cow Disease Affect Humans?
  • What Are the Symptoms of vCJD?
  • Is it Possible to Get vCJD From Eating Food Purchased in the U.S.?
  • Can You Get vCJD From Drinking Milk From an Infected Cow?
  • What About Other Products Made From Cow By-Products?
  • What Is the Current Risk of vCJD to Americans Traveling Abroad?
  • How Long Have Health Officials Been Concerned About Mad Cow Disease?
  • What Other Countries Have Reported Cases of Mad Cow Disease?
  • More

Mad cow disease, or bovine spongiform encephalopathy (BSE), is a transmissible, slowly progressive, degenerative, and fatal disease affecting the central nervous system of adult cattle. The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE.

Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue — the brain and spinal cord.

Common methods to eliminate disease-causing organisms in food, like heat, do not affect prions. Also, prions only seem to live in nervous system tissue.

A human version of mad cow disease called variant Creutzfeldt-Jakob disease (vCJD) is believed to be caused by eating beef products contaminated with central nervous system tissue, such as brain and spinal cord, from cattle infected with mad cow disease. For this reason, the USDA requires that all brain and spinal cord materials be removed from high-risk cattle — older cattle, animals that are unable to walk, and any animal that shows any signs of a neurological problem. These cow products do not enter the U.S. food supply. The USDA believes this practice effectively safeguards U.S. public health from vCJD.

According to the CDC, four deaths from vCJD have been identified in the U.S. However, it’s believed those cases were caused by consumption of meat outside the U.S.

It is important to clarify the differences between variant CJD and another form of the disease, referred to as classic or sporadic CJD. Classic CJD has no known cause and occurs each year at a rate of one to two cases per 1 million people throughout the world, including in the U.S. and countries where mad cow disease has never occurred. It is not linked to eating nerve tissue from mad cow disease-affected cattle — both vegetarians and meat eaters have died from classic CJD. CJD most commonly affects people over 65 and is usually fatal within six months from onset of symptoms.

The disease can affect all age groups and is very hard to diagnose until it has nearly run its course. In the early stages of vCJD, people have symptoms related to the nervous system, like depression and loss of coordination. Later in the illness, dementia develops. But only in advanced stages of the disease can brain abnormalities be detected by MRI (magnetic resonance imaging). vCJD is fatal, usually within 13 months of the onset of symptoms.

It is extremely unlikely that this would happen. To prevent mad cow disease from entering the country, since 1989 the federal government has prohibited the importation of certain types of live animals from countries where mad cow disease is known to exist. This ban includes meat products used in human, animal, and pet foods. In addition, prohibiting high-risk animals from entering the food supply and the removal of central nervous system tissue from the food supply help ensure that BSE is not a risk to consumers.

Milk and milk products are not believed to pose any risk for transmitting mad cow disease to humans. Experiments have shown that milk from mad cow-infected cows has not caused infections.

The FDA stops the importation of cosmetic and dietary supplement ingredients containing bovine materials from animals originating in the 33 countries where mad cow disease has been found or from animals at risk of being infected.

According to the CDC, the current risk of acquiring vCJD from any specific country appears to be extremely small. But that cannot be precisely determined because cattle products from one country might be distributed and consumed in others.

Mad cow disease has been of great concern since 1986, when it was first reported among cattle in the U.K. At its peak in January 1993, almost 1,000 new cases per week were identified. Concern about this disease grew significantly in 1996 when an association between mad cow disease and vCJD in humans was discovered.

The disease also has been confirmed in cattle born in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Israel, Japan, Liechtenstein, Luxembourg, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Switzerland, and the U. K.

Canada has also been added to the list of countries from which imports are restricted, although that ban has been lifted recently. Importation of minimal-risk meat products is now allowed from Canada.

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Symptoms, Causes and Treatments for vCJD

Written by Michael W. Smith, MD

  • Mad cow disease has hit the U.S. and questions about this mysterious disease abound. Here’s what you need to know about mad cow disease.
  • What Is Mad Cow Disease?
  • Does Cooking Food Kill the Prion That Causes Mad Cow Disease?
  • Does Mad Cow Disease Affect Humans?
  • What Are the Symptoms of vCJD?
  • Is it Possible to Get vCJD From Eating Food Purchased in the U. S.?
  • Can You Get vCJD From Drinking Milk From an Infected Cow?
  • What About Other Products Made From Cow By-Products?
  • What Is the Current Risk of vCJD to Americans Traveling Abroad?
  • How Long Have Health Officials Been Concerned About Mad Cow Disease?
  • What Other Countries Have Reported Cases of Mad Cow Disease?
  • More

Mad cow disease, or bovine spongiform encephalopathy (BSE), is a transmissible, slowly progressive, degenerative, and fatal disease affecting the central nervous system of adult cattle. The U.S. Department of Agriculture (USDA) has tested hundreds of thousands of cattle for BSE.

Researchers believe that the infectious agent that causes mad cow disease is an abnormal version of a protein normally found on cell surfaces, called a prion. For reasons still unknown, this protein becomes altered and destroys nervous system tissue — the brain and spinal cord.

Common methods to eliminate disease-causing organisms in food, like heat, do not affect prions. Also, prions only seem to live in nervous system tissue.

A human version of mad cow disease called variant Creutzfeldt-Jakob disease (vCJD) is believed to be caused by eating beef products contaminated with central nervous system tissue, such as brain and spinal cord, from cattle infected with mad cow disease. For this reason, the USDA requires that all brain and spinal cord materials be removed from high-risk cattle — older cattle, animals that are unable to walk, and any animal that shows any signs of a neurological problem. These cow products do not enter the U.S. food supply. The USDA believes this practice effectively safeguards U.S. public health from vCJD.

According to the CDC, four deaths from vCJD have been identified in the U.S. However, it’s believed those cases were caused by consumption of meat outside the U.S.

It is important to clarify the differences between variant CJD and another form of the disease, referred to as classic or sporadic CJD. Classic CJD has no known cause and occurs each year at a rate of one to two cases per 1 million people throughout the world, including in the U. S. and countries where mad cow disease has never occurred. It is not linked to eating nerve tissue from mad cow disease-affected cattle — both vegetarians and meat eaters have died from classic CJD. CJD most commonly affects people over 65 and is usually fatal within six months from onset of symptoms.

The disease can affect all age groups and is very hard to diagnose until it has nearly run its course. In the early stages of vCJD, people have symptoms related to the nervous system, like depression and loss of coordination. Later in the illness, dementia develops. But only in advanced stages of the disease can brain abnormalities be detected by MRI (magnetic resonance imaging). vCJD is fatal, usually within 13 months of the onset of symptoms.

It is extremely unlikely that this would happen. To prevent mad cow disease from entering the country, since 1989 the federal government has prohibited the importation of certain types of live animals from countries where mad cow disease is known to exist. This ban includes meat products used in human, animal, and pet foods. In addition, prohibiting high-risk animals from entering the food supply and the removal of central nervous system tissue from the food supply help ensure that BSE is not a risk to consumers.

Milk and milk products are not believed to pose any risk for transmitting mad cow disease to humans. Experiments have shown that milk from mad cow-infected cows has not caused infections.

The FDA stops the importation of cosmetic and dietary supplement ingredients containing bovine materials from animals originating in the 33 countries where mad cow disease has been found or from animals at risk of being infected.

According to the CDC, the current risk of acquiring vCJD from any specific country appears to be extremely small. But that cannot be precisely determined because cattle products from one country might be distributed and consumed in others.

Mad cow disease has been of great concern since 1986, when it was first reported among cattle in the U. K. At its peak in January 1993, almost 1,000 new cases per week were identified. Concern about this disease grew significantly in 1996 when an association between mad cow disease and vCJD in humans was discovered.

The disease also has been confirmed in cattle born in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Italy, Ireland, Israel, Japan, Liechtenstein, Luxembourg, the Netherlands, Poland, Portugal, Slovakia, Slovenia, Spain, Switzerland, and the U.K.

Canada has also been added to the list of countries from which imports are restricted, although that ban has been lifted recently. Importation of minimal-risk meat products is now allowed from Canada.

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what you need to know about mad cow disease

The Department of Veterinary Medicine of the Sverdlovsk Region warns owners of cattle about the danger of importing into the country from disadvantaged zones or countries of breeding stock, meat, canned food, offal and semi-finished products, meat and bone meal, sperm, embryos, technical fat, intestinal raw materials and other products and feeds of animal origin from ruminants. In order to prevent mad cow disease infection, it is necessary to inform veterinary clinics in a timely manner.

What is mad cow disease?

Bovine spongiform encephalopathy (BSE), or mad cow disease, is a slowly developing infectious prion transmissible disease of adult cattle, characterized by a long, up to 2.5-8 years, incubation period and manifested by damage to the central nervous system with 100% mortality.

Historical reference.

Spongiform encephalopathy was first reported in 1985-1986 in the UK under the name “mad cow disease”. In the next 10 years, BSE spread to other countries: France, Portugal, Switzerland, Germany, the Netherlands, Italy, Denmark, Slovakia, Finland, etc.

scrapie cattle (scrapie) – a similar agent (causative agent of sheep scrapie), found in meat and bone meal, which was included in the diet of cattle. In Russia, the disease has not been registered.

Economic damage.

BSE caused enormous economic damage to European countries, due to the fact that about 4 million heads of cattle were destroyed. The UK alone suffered an economic loss of £7 billion.

Epizootological data.

Under natural conditions, cattle are susceptible to BSE, especially at 4 years of age. The source of the causative agent of infection are sick and animals in the incubation period. The factors of transmission of the infectious agent are the products of slaughter of sheep with scrapie, and cattle with EH.

Course and symptoms of the disease.

The incubation period is from 2.5 to 8 years, in some cases it can be extended up to 25-30 years. The course of the disease is progressive, without remissions. The disease proceeds without an increase in body temperature of the animal, with continued appetite. Despite a normal appetite, cows have reduced milk production.

The clinical manifestation of the disease is characterized by signs of damage to the central nervous system.

Three types of nervous phenomena are detected during GE.

  • The first type of nervous phenomena is accompanied by the development in animals of a feeling of fear, nervousness, aggressiveness, gnashing of teeth, restlessness, timidity. The above symptoms occur in 98% of sick animals.
  • The second type of nervous phenomena is characterized by the presence of movement disorders in sick animals: trotting movements, “raking in the front limbs”, “lowering” of the hind legs, raised tail
  • In the third type of nervous phenomena, there is a violation of sensitivity, when in sick animals we note hyperesthesia with noise, touch and light. The duration of the disease is from several weeks to 12 months or more. The disease always ends in the death of the animal.

Pathological changes.

At autopsy of dead animals, characteristic pathoanatomical changes are either absent or mild.

Diagnosis.

Send to the laboratory for diagnostic tests:

– bovine brain after testing for rabies and other viral infections after the diagnosis was not confirmed;

– the brain of cattle from meat processing plants (0. 01% of slaughtered animals older than 3 years).

Pathological material (brain) is taken from animals with clinical signs of damage to the central nervous system). In this case, the brain for research must be taken from animals immediately after their slaughter or death.

Specific prophylaxis.

BSE does not produce either cellular or humoral immunity, so no vaccine has been developed in the world to date.

Treatment.

Treatment is ineffective, the prognosis for the disease is unfavorable.

Prevention.

The basis of prevention for prosperous countries is: preventing the importation of pedigree cattle, meat, canned food, by-products and semi-finished products, meat and bone meal, semen, embryos, technical fat, intestinal raw materials and other products and feeds of animal origin from ruminants; careful control over purchases of breeding stock and biological tissues, especially from disadvantaged countries; prohibition of feeding ruminants with meat-and-bone and bone meal from cattle and sheep.

If BSE is suspected, contact a veterinary clinic.

In order to prevent bovine spongiform encephalopathy, owners of susceptible animals must strictly comply with the requirements provided for in paragraph 7 of the Veterinary Rules for the implementation of preventive, diagnostic, restrictive and other measures, the establishment and lifting of quarantine and other restrictions aimed at preventing the spread and eliminating foci of large spongiform encephalopathy approved (hereinafter referred to as the Veterinary Rules), including paragraphs 6 and 7 of clause 7 of the Veterinary Rules regarding the incineration of waste from the slaughter of susceptible animals and the prohibition of feeding animals with meat and bone, bone meal, protein briquettes, as well as other feed and feed additives for animals containing ruminant proteins in their composition.

Mad cow disease

Bovine Spongiform Encephalopathy (BSE) or Mad cow disease and sheep and goats, chronic wasting disease in deer ( zombie deer), Creutzfeldt-Jakob disease in humans. Like all prion diseases, mad cow disease has a dangerously long incubation period and can manifest itself 5-8 years after infection.
Mad cow disease was first diagnosed in the UK in 1985, and it took some time to identify the disease. The infection of such a large number of livestock occurred due to the use of feed containing meat and bone meal with prion proteins.

The disease causes very serious economic damage. In the UK, about 4 million cattle were destroyed; dealt a serious economic and reputational blow to agriculture.
Thanks to the OIE’s stringent measures to control the use of feed of animal origin, the movement of animals and regular post-mortem diagnostics, mad cow disease has virtually disappeared. Sometimes isolated cases are recorded.

Spongiform encephalopathy prions have been shown to be transmitted to humans, causing Creutzfeldt-Jakob disease.

  • Animal species: Cattle
  • Disease category: Disease of the nervous system
  • Anthroponosis: Yes
  • 9009 0 Contagious: Yes
  • Treated: No
  • Natural focal: No
  • Age groups: All

🔴 Species affected

Cattle. Cows get sick, bulls get infected less often.

🔴 Distribution

The disease is registered in almost all European countries, Asia, the Middle East, South and North America, Japan and Australia.

🔴 Etiology

Infection occurs through feed of animal origin: meat and bone meal, milk powder, etc. Especially dangerous are products and preparations containing tissues of the spinal cord and brain. There are no data on animal-to-animal transmission and very little data on infections transmitted from mother to fetus.
The disease is slow-moving, and the diseased animal is often slaughtered before clinical signs appear. According to the OIE, after infection, clinical signs appear, depending on the age and immunity of the animal, in the range from two to eight years.
Prion is resistant to heat and drying. This means that meat and milk from sick animals cannot be used as food or fed to other animals. Cases of infection of large felines in zoos have been reported when feeding meat from cows with mad cow disease.
Prions persist in the environment for a long time. There is evidence that prions live in water for about a year, and in soil for about three years. Even after passing through the digestive system of birds and mammals, prions retain their ability to remain infectious.
In diseased animals 100% death.

🔴 Pathogenesis

The origin, course and spread of the disease still require scientific research.
Mad cow disease is caused by a special type of protein called a prion. This protein has a self-sustaining altered form. When a defective protein enters the body, it causes the surrounding normal proteins to assume the same shape. This process is in the nature of a chain reaction and leads to the formation of large or cluster-like vacuoles in neuronal cells, and the brain tissue acquires a spongy structure. These changes are irreversible.

The uniqueness of the prion is that it does not have hereditary information in its structure and, if the configuration of the protein polypeptide chain matches, is able to overcome the species barrier. This is confirmed by an experiment on infecting mice with sheep prions (scrapie). It is assumed that the epidemic in the UK in 1985-1986 began with the purchase of a large batch of meat and bone meal, the raw material for which was infected scrapie sheep.

📌 There are two strains:

  1. Classic mad cow disease. Transmitted through prion-contaminated food. It is assumed that young animals get sick, and then the disease slowly develops with irreversible consequences.
  2. Atypical mad cow disease . Occurs spontaneously, and it is not yet known how infection occurs. Only old animals get sick. Infection through food in this case is excluded. It is assumed that in an old animal, the body ceases to maintain a constancy of the internal environment and proteins begin to fold into the form of a prion on their own.

Mad cow disease is listed by the OIE and all countries are required to report cases of the disease. Quarantine restrictions are imposed on the country: the export of livestock, meat, dairy and other products with additives of animal origin is prohibited.
Mad cow disease must be differentiated from encephalitis, rabies, tetanus, poisoning.

🔴 Clinical signs

  • Wasting;
  • Loss of productivity;
  • Violation of coordination of movements;
  • Hypersensitivity to sudden sounds and touch;
  • Aggressive behavior;
  • Tremor;
  • Motor retardation.

🔴 Autopsy picture

No serious changes in the body are found at autopsy, except in cases of severe exhaustion.
Spongy lesions limited to the brain and spinal cord.
Fluid-filled cavities are clearly visible on a histological section of the brain tissue. Cells show single or multiple vacuoles.

🔴 Diagnosis

Diagnosis is based on clinical signs.
Currently, there is no test that can reliably confirm the presence of mad cow disease in vivo.
Diagnosis is postmortem based on histological examination of the medulla oblongata.
The diagnosis is confirmed by immunochemical or immunohistochemical detection of a specific prion protein in the medulla oblongata.