Listed Disease

Mammalian tuberculosis (mTB) 

Mammalian tuberculosis (mTB) is a chronic bacterial disease and zoonosis that affects livestock, wildlife, and humans. It includes bovine tuberculosis and other forms of tuberculosis caused by members of the Mycobacterium tuberculosis complex. The disease threatens animal and human health, disrupts ecosystems, and causes major economic losses, especially in low-income regions. Control relies on biosecurity, testing, and slaughtering or segregating of infected animals, with new strategies under trial. It is a WOAH-listed disease, meaning cases must be notified to WOAH.

Page last reviewed: August 2026

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    What is mammalian tuberculosis? 

    What is mammalian tuberculosis? 

    Mammalian tuberculosis (mTB) is a chronic infectious disease that affects cattle, sheep, goats, equines, pigs, cats and dogs, and wildlife species such as wild boars, deer, and antelopes. When it affects humans, it is called zoonotic tuberculosis, or zTB.

    The disease is slow and can take months or years to reach the fatal stage. It often goes unnoticed at first, spreading silently through herds. Infected animals may appear healthy for weeks, while transmitting the bacteria. Over time, it leads to respiratory issues, fever, diarrhoea, weight loss, swollen lymph nodes (tubercules), and ultimately death. For communities that depend on livestock for food, income, and cultural value, mTB can reduce livestock productivity, threaten food supply and strains livelihoods. In wildlife, persistent infection can undermine conservation efforts and disturb ecosystems. 

    Though a vaccine exists, its use in livestock is restricted in most countries due to challenges in disease surveillance: vaccinated animals may test positive, making it hard to distinguish them from infected ones. As a result, most countries rely on strict biosecurity measures, testing, and slaughtering to contain outbreaks. While high-income countries have largely controlled the disease in cattle, wildlife remains a reservoir (badgers in the United Kingdom, deer in the United States of America, possums in New Zealand) making full eradication difficult. In Africa and parts of Asia, where the disease is widespread and harder to manage, mammalian TB continues to impact animal and human welfare. 

    What makes mammalian tuberculosis a global concern?

    Mammalian tuberculosis (mTB) threatens rural livelihoods, animal welfare, and public health worldwide.
    Enforcing strict biosecurity measures and routine testing in herds is essential to detect infections early,
    limit transmission, and protect both communities and ecosystems from its devastating impacts. 

    How does mTB affect communities?

    Mammalian tuberculosis reduces livestock productivity and raises animal welfare concerns. For farmers, managing infected animals and complying with disease control procedures can cause financial hardship. The impact extends those involved in livestock supply chain, including butchers, traders, and market vendors, especially when trade restrictions are imposed to contain outbreaks.

    In wildlife, mTB can act as reservoir for mTB maintaining infection within their populations and transmitting it back to livestock. Confirmed examples include badgers, deer, and possums. In these settings, controlling the disease in livestock alone is insufficient as the wildlife reservoirs can act as a source of infection to livestock. Beyond economics, mammalian tuberculosis is also a public health risk. As a zoonotic disease, it can spread from animals to humans, most often through the consumption of unpasteurised dairy or close contact with infected animals.

    An estimated

    147, 000

    cases of zoonotic tuberculosis result in
    approximately 12, 500 deaths each year.

    The bacterium Mycobacterium bovis, a common cause of mTB, is responsible for an estimated 10% of human tuberculosis cases, though the true figure is likely underreported due to limited surveillance in many countries. Unlike human TB caused by M. tuberculosis, zoonotic TB (zTB) which can be caused by M. bovis and other members of the Mycobacterium tuberculosis complex often affects organs other than the lungs and is naturally resistant to pyrazinamide, one of the main antibiotics used in treatment. This makes the disease harder to diagnose and treat, particularly in low-resource setting and the true global burden of zTB remains uncertain due to limited surveillance and the lack of routine species-level diagnosis in most countries.

    How does mammalian tuberculosis spread? 

    ​​​Mammalian tuberculosis is caused by bacteria from the Mycobacterium tuberculosis complex, most often M. bovis, but also M. caprae, M. microti, M. orygis, and M. pinnipedii.  While cattle are most commonly affected, mTB spreads across many mammals, including goats, camels, pigs, equines, and wildlife species like buffaloes and badgers.

    The disease progresses slowly, often taking months or years to become fatal. Infected animals can shed bacteria and spread disease before showing any clinical signs, making undetected animal movement a key transmission route. Transmission mainly occurs through aerosols, when infected animals inhale droplets from a sick animal’s cough or breath. Because the disease can remain dormant, apparently healthy animals can still transmit it, particularly during herd mixing, trade, or transport. Young animals face higher risk, often infected through milk, saliva, or colostrum. Malnutrition, pregnancy, and weakened immunity also increase susceptibility. The disease can spread through contaminated feed, water, mucous membranes, broken skin, or contact with infected bodily fluids. 

    Zoonotic transmission to humans occurs mainly through raw or undercooked dairy and meat, especially where pasteurisation access is limited. Farmers, slaughterhouse workers, and traders face direct exposure risk through inhalation or contact with infected animals. In areas with high human TB rates and close human-livestock contact, transmission can also flow from humans to animals. This has been documented for M. tuberculosis, M. bovis, and M. orygis, underscoring the bidirectional nature of transmission at the human-animal interface.​​ 

    How does mTB spread? An explainer

    Interactive infographic available

    Main infection routes

    For animals (mammalian tuberculosis) 

    • Inhalation of cough, sneeze or breath of infected animals 
    • Ingestion of milk or colostrum of mother to young 
    • Contact with infected urine, feces or wounds 

    For humans (zoonotic tuberculosis) 

    • Consuming unpasteurised milk and milk products 
    • Consuming contaminated or raw meat from infected animals 
    • Close contact with infected animal though inhalation or handling of such animals 

    How do you know if an animal is infected? 

    Mammalian TB (mTB)  causes respiratory signs including intermittent hacking cough, shortness of breath, and low-grade pneumonia. Early signs include appetite loss, weight loss, weakness, diarrhoea, and fluctuating fever. Enlarged lymph nodes forming tubercules are a distinctive marker and gave the disease its name. mTB can remain silent for months or years before symptoms appear, during which infected animals can unknowingly transmit disease. Symptom onset speed varies with immune status and exposure level. 

    Since clinical signs are not specific to mTB, diagnosis cannot rely on symptoms alone. The tuberculin skin test is the standard diagnostic tool: tuberculin is injected under the skin, with reaction measured after 72 hours. A blood test may follow to improve accuracy. Laboratory culture provides definitive confirmation in suspected or confirmed cases. All testing follows WOAH Terrestrial Manual. 

    Questions and answers about mammalian tuberculosis​​ 

    Are there alternatives to test-and-slaughter for mTB control? 

    Yes. While test-and-slaughter is currently the method to control mTB in countries having established control programmes, it is not always suitable. For ethical, cultural, or economic reasons, some countries have explored alternative approaches such as test and segregation, biosecurity measures, BCG vaccination, and movement controls. WOAH guidelines recognise that alternative and complementary control measures may be appropriate where test-and-slaughter strategies are not feasible or acceptable. A pilot study in Ethiopia using these approaches has shown promising results in reducing disease spread in a resource-limited setting.

    Can wild animals get infected too?  

    Yes. Wild animals can become infected through direct contact or by sharing grazing areas or water sources with infected livestock or other reservoirs species and can then spread it further. Examples include badgers (UK, Ireland), wild boars (Spain), buffalo (South Africa), possums (New Zealand), and deer (USA). Control in wildlife practises include vaccination and slaughter, with badger vaccination approved in the UK and Ireland. 

    Can humans catch the disease?  

    Yes. Mammalian tuberculosis is a zoonotic disease, meaning it can spread from animals to humans. While M. bovis is main causal agent of bTB, other species from MTBC complex  (M. tuberculosis, M. africanum, M. caprae, M. orygis, and M. microti) are potentially zoonotic and can lead to zoonotic tuberculosis (zTB). It differs from the more common human TB and is less widespread, but still poses a serious health risk, especially in areas with close human-animal contact or consuming contaminated or unpasteurised dairy products. 

    Is there a vaccine for mammalian tuberculosis? 

    Yes. The only vaccination against mammalian tuberculosis is Bacillus Calmette–Guérin (BCG) – a live attenuated strain of M.bovis used in both human and animal vaccines. Its uptake in livestock is limited since vaccinated animals can test positive in routine tuberculin based diagnostic tests, making them indistinguishable from infected animals. However, this may change: tests capable of making this distinction are currently  being validated. BCG vaccination of badgers is approved in the UK and Ireland, and trials are underway in the UK and Mexico to support broader and more effective use of BCG in livestock and wildlife. 

    Why can’t we treat infected animals with antibiotics?  

    Treating animals with antibiotics is impractical due to the long duration, high cost, and complex dosing needed often six months or more. There is a potential risk that treated animals could continue to shed and transmit MTBC species to other animals. Worse, M. bovis is naturally resistant to pyrazinamide, a key TB drug. Using antibiotics improperly also increases the risk of antimicrobial resistance.  

    How does mTB disrupt ecosystems? 

    Mammalian tuberculosis can spread silently in wildlife, weakening key species and altering predator-prey dynamics. Infected animals may decline in number or change in behaviour, leading to biodiversity loss, imbalance in ecosystem functions, and even local extinctions of endangered species. As the disease persists in wild reservoirs, it becomes harder to control, threatening both natural ecosystems and the livelihoods that depend on them. 

    Prevention and control

    ​​​Prevention and control

    Mammalian tuberculosis (mTB) spreads quickly through herds—with the added danger that infected animals can look healthy for months. It can jump to other species, including wildlife and humans. Since the vaccine can interfere with testing results, control mostly relies on biosecurity, testing, and slaughtering, though new solutions are being experimented with, such as vaccinations and
    test and segregation.

    Countries and individuals can prevent or control mammalian tuberculosis outbreaks by: 

    Respecting biosecurity measures at all times

    and raising awareness about the disease among livestock farmers, abattoir workers, butchers, and animal health professionals

    Testing cattle systematically and individually

    and implementing intensive surveillance systems, including on-farm visits, individual animal identification, traceability, and movement controls

    Segregating or slaughtering

    infected animals

    Collaborating regionally and internationally

    to coordinate control and eradication efforts

    Find out what you can do to
    prevent and control mTB outbreaks

    You are:

    WOAH icon farmer or aquatic producer

    A farmer

    icon for Aquatic animal health professionals WOAH

    An animal health professional

    icon for a veterinary authority WOAH

    A veterinary authority

    A butcher or abattoir worker

    Farmers: what to do to prevent
    or control an mTB outbreak 

    As a farmer, you have a key role in protecting animals from mammalian tuberculosis and preventing its spread to other animals. By maintaining rigorous biosecurity measures, having your animals regularly tested, looking out for tell-tale signs of the disease, and reacting in a timely and appropriate manner to contain the disease if a case is suspected.

    ​​​Here is what you can do to prevent mTB: 

    • Get mTB-free status certification: certified herds may get better access to markets and higher selling prices. 
    • Track your animals through efficient and updated identification systems. 
    • Clean and disinfect farm equipment and facilities regularly, including the milking room, animal feeders and drinkers, with disinfectants that are effective against Mycobacteria. Replace housing soil regularly.
    • Control the introduction of new animals in herds that are free of the disease. 
    • Limit contact between animals in the same area, for example with double fencing to prevent nose-to-nose contact between animals on neighbouring farms.  
    • Keep track of the mTB situation in your region and reinforce biosecurity measures in case of an outbreak near you.  

    ​​​Here is what you can do to control mTB: 

    • Report suspected mTB cases to your veterinarian or to the local animal health authorities immediately.
    • Test the entire herd with professional help. 
    • Isolate sick animals. They must be kept apart from non-infected animals for life. Healthy calves must be separated from their mothers. They are not to be sold to other farms. They should not share pasture with non-infected animals.
    • Separate grazing, milking, and all other management areas to respect strict quarantine of sick animals. If it is not feasible, sick animals must be culled.
    • Have milk from infected animals pasteurised or boiled before consumption. 

    Animal health professionals: what to do to prevent or control an mTB outbreak

    As an animal health professional, you have a critical role to play in the timely detection and control of mTB cases. Your intervention may be the difference between a few isolated cases and an epidemic across herds and species. 

    ​​​Here is what you can do to prevent or control mTB: 

    • Train on surveillance and testing programmes. 
    • Confirm mTB diagnoses by collecting appropriate samples and running tests that follow procedures set out in the WOAH Terrestrial Manual. Animals on farms and abattoirs should be tested regularly, in line with your country’s surveillance programme. 
    • Report suspected and confirmed mTB cases to veterinary authorities immediately. 
    • Promote hygiene and biosecurity procedures with local farmers, butchers, and abattoir workers. 

    Veterinary authorities: what to do to prevent or control an mTB outbreak  

    As a veterinary authority, you play a key role in shaping your country’s mTB control strategy. There is no one-size-fits-all approach when it comes to this disease strategies must consider local farming practices, wildlife reservoirs, and public health risks. While testing and killing is effective, alternatives like biosecurity, test and segregation, and vaccination are gaining ground, especially in low-resource settings. Some countries also use varying forms of test and segregation in early stages, then switch to testing and killing methods in the final stages. 

    Mammalian tuberculosis is a WOAH-listed disease. This means that officials from Member countries must report cases of the disease to the Organisation. This is necessary for us to keep track of epidemics and, when relevant, to inform other Members of current outbreaks. Disease notification is also an integral part of any efficient early detection and warning system. 

    Notify WOAH about mTB on WAHIS 
    Notify WOAH by email

    Here is what you can do to prevent or control mTB: 

    • Notify WOAH of any confirmed mTB cases immediately and closely monitor the animal health situation in your country and region.
    • Collect data on the ground to fuel your country’s or region’s surveillance programme.  
    • Design national mTB response plans based on collected data. 
    • Strengthen Veterinary Services through training, networking, and by providing laboratory diagnostics tools. WOAH’s PVS Pathway programme offers guidance. 
    • Promote hygiene and biosecurity procedures at farm and abattoir-levels through awareness and information campaigns on mTB. 

    What about vaccines?

    The only vaccine currently available for M. bovis in cattle is BCG a live, weakened strain of the bacteria. It has been used safely in humans for over a century and is one of the most widely administered vaccines in the world. While BCG does not fully prevent infection in cattle, it can reduce the risk, lessen symptoms, and slow transmission. 

    Large-scale trials are underway in countries like the UK and Mexico, but BCG is still banned for cattle use in many places due to the false positives it can cause in routine mTB tests. For vaccination to move forward, countries will need new diagnostic tools that can tell the difference between vaccinated and truly infected animals, or an improved vaccine. 

    It is also essential to keep cattle vaccine supply chains separate from human ones, to avoid disruptions in global health programs. The science is advancing but careful planning is key to making cattle vaccination a safe, scalable option. 

    ​​​Butchers and abattoir workers: what to do to prevent or control an mTB outbreak

    As a butcher or abattoir worker, your role is vital in preventing the spread of mammalian tuberculosis. By applying strict hygiene, following sanitary protocols, and ensuring regular testing, you help protect both animal and human health, and safeguard an entire economic chain that depends on healthy livestock. 

    Here is what you can do to prevent or control mTB: 

    • Adopt hygiene procedures and biosecurity principles, including the regular clearing and disinfecting of all surfaces in contact with animals while wearing protective gear. Dispose of all waste immediately. 
    • Maintain an up-to-date record of equipment, vehicle, and holding yard cleaning, and follow it diligently. 
    • Train on safe practices and learn about mTB. 
    • Keep track of the mTB situation in your region and reinforce biosecurity measures in case of an outbreak near you.  
    • Monitor health in your establishment through routine carcass and post mortem meat inspections: look for tubercules in the lungs, lymph nodes, intestines, liver, spleen, pleura, and peritoneum. This could help detect infected animals and herds through traceability and prevent unsafe meat from entering the food chain.
    • Promote pasteurisation of dairy products. 
    • Implement rigorous testing of dairy products and meat. 
    ​​​Mammalian tuberculosis today

    ​​​Mammalian tuberculosis today

    Mammalian tuberculosis (mTB) remains widespread and largely uncontrolled across Africa, Asia, Latin America, and much of the Middle East. Some countries, mostly high-income nations, have successfully implemented systematic control programmes and are now considered mTB-free in livestock. Their success is largely due to the consistent application of the test-and-slaughter method. Meanwhile, others are exploring alternative strategies like large-scale vaccination or test and segregation. 

    In countries with robust surveillance, mTB cases are rare, but in regions with limited monitoring, the disease can continue to spread undetected especially through wildlife reservoirs, even where livestock is regularly tested. 

    Different strains for different regions 

    There is growing evidence that different types of bacteria from the Mycobacterium tuberculosis complex dominate in different regions. While M. bovis is the leading cause of mTB in Africa, much of Western Europe, and the Americas, M. caprae is more common in Central Europe. In South Asia, mTB is caused not only by M. bovis, but also by M. caprae, M. orygis, and even M. tuberculosis.

    Managing mTB infections in wildlife

    ​​​Even in countries considered free of mTB in livestock, wildlife reservoirs remain a serious challenge. Infected wild animals have been detected in several regions, including elk in parts of Canada, wild boar and deer in the Iberian Peninsula, badgers in Ireland and the UK, brush-tailed possums in New Zealand, African buffalo in South Africa, and white-tailed deer in parts of the United States. In these areas, spillover hosts including rodents and small mammals as well as carnivores and ungulates can carry and spread the disease further. 

    In regions where livestock control is weak or inconsistent, the infection of wildlife creates an added barrier to eradication efforts. It not only undermines disease control in domestic animals but also poses a major risk to biodiversity, threatening the stability of ecosystems and complicating long-term prevention strategies. In an effort to protect biodiversity, some countries have designated TB quarantine zones such as Kruger Park in South Africa.   

    Controlling diseases in wildlife is complicated by nature. It requires strong partnerships between Veterinary Services, wildlife authorities, and local communities through a One Health approach. 

    Latest news on mammalian tuberculosis 

    How we fight it

    How we fight mammalian tuberculosis


    Mammalian tuberculosis (mTB) has far-reaching impacts, threatening public health, animal welfare, livelihoods, economies, and ecosystems. As it sits at the crossroads of humans, animals, and the environment, tackling mTB demands coordinated action through a One Health approach.

    To address this, the World Organisation for Animal Health (WOAH), together with the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the International Union Against Tuberculosis and Lung Disease (The Union), launched a Roadmap to tackle zoonotic tuberculosis in 2017. We also support research and provide specific tools to help Members effectively prevent, track, and contain mTB outbreaks.

    A One Health roadmap to tackle zoonotic tuberculosis

    The first-ever global roadmap to tackle zoonotic tuberculosis embraces a One Health approach, recognising that human, animal, and environmental health are deeply interconnected. Launched with international partners, the roadmap urges collaborative action from governments, donors, researchers, NGOs, and the private sector across political, financial, and technical domains. 

    The roadmap aims to achieve three main objectives: 

    To improve the scientific evidence base

    • Collect and report more complete and accurate data. 
    • Improve diagnosis in people. 
    • Address research gaps. 

    To reduce transmission between animals and humans

    • Ensure safer food. 
    • Improve animal health.  
    • Reduce the risk to people.

    To strengthen collaboration across sectors

    • Increase awareness, engagement, and collaboration.
    • Develop policies and guidelines. 
    • Implement joint interventions. 
    • Advocate for investments. 

    Together, these priorities form a clear path towards controlling mammalian tuberculosis in animals and zoonotic tuberculosis in people, protecting health and livelihoods worldwide.  

    Turning the roadmap into action: new guidelines for mTB control 

    The work of WOAH’s ad hoc group on the implementation of the zoonotic TB roadmap led to the release of new guidelines in 2024, designed especially for countries where test and slaughter is not a viable option. These guidelines offer practical, adaptable recommendations to help veterinary authorities tailor their response based on local realities. 

    The document outlines biosecurity measures and introduces innovative strategies like livestock vaccination and test and segregation. A pilot project in Ethiopia has already shown encouraging results, offering a model for other regions facing similar challenges. 

    To mark the launch, WOAH hosted a webinar with over 200 participants, presenting how the guidelines were developed and how they can be applied. The Organisation is now actively sharing these tools through social media campaigns, and is preparing advocacy materials to support wider awareness and action against mammalian tuberculosis. 

    A webinar on mTB control

    Explore a set of five informative webinars exploring the holistic approaches to controlling mycobacterium tuberculosis complex in livestock, extending beyond test and slaughter methods.

    Supporting research for science-based action   

    WOAH actively supports and coordinates international research to ensure that our guidelines and policy recommendations reflect the latest scientific evidence. WOAH is a member and co-host of STAR-IDAZ, the International Research Consortium on Animal Health, which drives global collaboration to address animal health challenges. In 2024, the consortium launched new research roadmaps on mammalian tuberculosis, aiming to close gaps in diagnostics, vaccines, and disease control. 

    In parallel, WOAH continues leading the search for a replacement for the depleted international standard bovine tuberculin (ISBT)—a key reference standard for quality control tests for purified protein derivative bovine tuberculins that are used in MTBC surveillance, diagnosis and export certification. The current reference standard was produced in 1986 and is becoming depleted. Since 20175, the WOAH ad hoc Group on ISBT met regularly to identify a replacement of this international standards.