Johne’s disease (paratuberculosis) in ruminants
A slow, silent, untreated infection that is expensive long before it becomes visible. Understand its mechanism, know how to detect it and, above all, know how to prevent it.
- Cattle
- Sheep
- Goats
- Wild ruminants
The essentials in 5 points
- A disease found on every continent, transmitted by the faecal–oral route and caused by Mycobacterium avium subsp. paratuberculosis (MAP).
- A very long incubation : the disease is silent during years and called “ iceberg ” — it is difficult to diagnose.
- Main symptoms : diarrhea (especially in cattle), weight loss, weakness, and death.
- Economic losses by reduction in milk production and of meat, and by premature culling.[1]
- No treatment : only prophylaxis, in 5 pillars — pasture hygiene, housing hygiene, manure management, day-to-day animal management (with young animals protected as a priority), and vaccination.
Johne’s disease, also called Johne’s disease, is a disease infectious and contagious caused by bacteria Mycobacterium avium subspecies paratuberculosis (MAP). It affects ruminants — cattle, sheep and goats — but also wild ruminants : deer, roe deer, mouflons.
It is a disease global distribution[2], described as « silent ” or “ iceberg » : for one visibly sick animal, the herd has many others, infected and contaminants, but without the slightest sign.
Without treatment available, everything depends on three levers : understand the mechanism of infection, detect at the right time And apply rigorous preventive measures. This factsheet addresses each of them in turn.
1. The responsible agent : the MAP bacteria
| Body | Mycobacterium avium subspecies paratuberculosis (MAP) |
|---|---|
| Biological characteristics | Gram-positive coccobacillus, acid-fast — it’s the Ziehl-Neelsen stain, and not the Gram, which reveals it to microscope. Very similar to the tuberculosis bacillus. |
| Location | Intracellular, in macrophages → difficult to eliminate by the immune system |
| Generation time | 2 to 10 days depending on the strain → slowly progressive disease[3] |
| Resistance | From several months to more than a year in the environment. Favorable conditions : humid soils, acidic soils, cold, shade. |
| Sensitivity | UV rays · heat · desiccation. On the disinfectant side, MAP resists most common products : only the tuberculocidal disinfectants are actually active[4]. |
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How long does it survive in the environment ?
These are maximum reported durations. The bacteria does not multiply not outside an animal : its infective power decreases markedly in a few months, especially faster than the plot is sunny — shade and humidity preserve.
2. Transmission and epidemiology
How does the bacteria circulate ?
- Fecal-oral route — main route. By food, soil or water contaminated by feces.
- Milk and colostrum. An infected female excretes the bacteria in her milk and colostrum. The risk is multiplied if the milks of several animals are mixed : a single infected animal then contaminates a whole batch of young animals.
- Transplacental route. The fetus can be infected even before to be born : approximately 9 % of fetuses of infected mothers without symptoms, and up to 39 % when the mother is in phase clinic[11]. A calf born to a sick mother can therefore already be a carrier.
Who becomes infected, and when ?
- Calves under 6 months are the most sensitive : their immune system is still poorly developed.
- They mainly become infected during feeding, on soiled teats.
- Infection remains possible in older animals, but their system A better developed immune system allows the bacteria to be eliminated more often.
- The vast majority of sick adults were infected during their first months of life — clinical signs only appear years later.
A disease much more widespread than we think
Johne’s disease is rarely visible, but it is present in a large part of the herds. Surveys carried out in France and Europe between 2009 and 2024 give, for dairy herds :
infected herds
Europe[12]
infected herds
Italy, ELISA[13]
infected herds
France[14]
These figures relate to the proportion of herds affected, and not on the proportion of affected animals in a given herd. Within an infected herd, serological surveys locate the intra-herd prevalence most often between 3 and 10 % of animals according to the species, region and age of infection : 3.6 % on average in dairy cattle in Switzerland[16], 4.5 % in sheep and 5.1 % in goats in Sicily[17], 6.3 % in sheep in the Marches[13], and more in herds where the infection has been established for a long time. These values are floors : serology only identifies animals already advanced in the infection and allows some of the silent carriers to pass. There actual proportion of infected animals in an affected herd is therefore clearly superior — that’s the whole meaning of the image of the iceberg (see below).
THE wild ruminants are important reservoirs[2] of bacteria MAP : deer, roe deer, mouflons. Their access to pastures for domestic herds must be limited.
Johne’s disease is listed in category E of the health law European animal welfare — Regulation (EU) 2016/429 and Implementing Regulation (EU) 2018/1882[5] —, that is to say a disease subject to surveillance. It is neither a health hazard first or second category, nor an illness covered by a policy sanitary : it does not cause no compulsory slaughter, no restrictions regulation of movements.
In France, the struggle is voluntary and organized by the Groups of health defense (GDS), around two axes : a guarantee of livestock low risk (securing introductions) and a control plan by screening generalized[6]. There is no national plan for small ruminants, but some GDS offer local plans.
3. Mechanism : the three phases of infection
The infection always follows the same loop : an environment soiled by feces, an animal that ingests the bacteria, slowly multiplying in the mucous membrane intestinal, then excretion which recontaminates the environment (see the diagram of the infectious cycle, above).
One of the main characteristics of paratuberculosis is its very long incubation period. The disease is broken down into three phases.
Silent infection
Early and intense cellular response. The animal is infected but does not excrete not or too little to be detected, and remains seronegative : it escapes testing.
Transitional phase — the immune fight
Appearance of fecal excretion and serum antibodies. PCR and ELISA tests become positive, but sensitivity remains moderate.
Clinical disease[2]
Collapse of the cellular response, massive excretion and high seropositivity. Clinical signs : diarrhea, weight loss, death.
The deadlines indicated are counted from infection, which occurs most often in the first months of life. These three phases overlap from one animal to another : the rhythm is individual, and no date applies to an entire herd. Incubation lasts from a few months to several years — the signs most often appear 2 to 6 years later contamination in cattle, who rarely express them before the age of 2, and Rare cases occur up to 15 years after infection. In small ruminants and deer, the disease can occur before a year[4].
A negative result does not exclude infection : tests must be repeated and interpreted at the herd level, never on a single isolated animal.
What happens in the intestine
The infection begins with ingestion of the bacteria, primarily orally, and then their multiplication in the intestinal mucosa. Due to the time of particularly long generation of MAP, the disease sets in slowly : it can take several years for symptoms to appear or even never appear in certain infected animals.
The germs are then phagocytosed by macrophages. Two outcomes are then possible :
1. The infectious agent is eliminated
Cellular immunity overcomes the bacteria. This immunity increases with time — which explains that calves become infected more easily than adults, whose immune system is capable of eliminating the pathogen.
2. The bacteria resists
It survives inside the macrophages, then disseminates into the lymph nodes regional lymphatics. Infected animals may already begin to excrete bacteria, without any visible symptoms.
Only cellular immunity is effective against MAP bacteria.
Following a decreased immunity — often caused by stress, birth or concomitant infection — the bacteria multiplies more easily and can spread throughout the body, mainly destroying the intestine. This is followed by reduced nutrient absorption, diarrhea and progressive weight loss leading to cachexia and death, as well as numerous other symptoms.
Excretion of the bacteria through feces is very important and constitutes the main source of environmental contamination. This excretion can begin 2 to 5 years before the first clinical signs : it is why we speak of a “ silent ” disease. Animals without signs clinics are therefore important sources of transmission — even if shedding remains much higher in animals showing clinical signs.
4. Why do we speak of “ iceberg ” disease?
Due to the late and non-systematic appearance of clinical symptoms, a clinically ill animal[2] means 15 to 25 other infected animals without symptoms in the herd, depending on the level of infection of the herd.
We also observe in these animals an excretion of bacteria as well as a decrease in production. These losses are silent and often pass unnoticed, which makes the diagnosis all the less obvious.
5. How much does paratuberculosis cost?
Because they take hold years before the first visibly sick animal, the Losses most often remain invisible. Reported to an animal’s career contaminated, however, they number in the hundreds to several thousand euros.
Loss on the career of an infected animal, per animal.
This cost adds up several loss items which accumulate throughout throughout the life of the animal :
- Fall in milk production
- Reduced fertility and prolificacy
- Stunted growth and weight loss (meat)
- Premature reform affected animals
- Increased mortality
- Edema, pitted hair, deterioration of general condition
What an infected animal loses, sector by sector
Here is the loss on a year, For a single infected animal : in euros, then as a share of what it actually brings in.
THE gross product, this is the turnover generated by the animal. L’EBE (gross operating surplus), this is what remains once expenses paid, before remuneration for work : this is where the loss makes the worse.
Annual loss per infected animal and weight of this loss in the workshop economy
Euro scale : 0 to 600 € · percentage scale : 0 to 60 %
What these amounts add up to : the drop in production dairy, early culling, depreciation of carcasses, return to heat and lost calvings, and mortality.
All these positions deepen before diarrhea, weight loss and death. This is why they are almost always underestimated in breeding : when an animal becomes visibly ill, most of the cost has already passed.
6. Symptoms and lesions[8]
Johne’s disease is a chronic disease. The signs clinical differences differ markedly between cattle and small ruminants.
| Sign | What we observe |
|---|---|
| Diarrhea | Characteristic sign. Constant to intermittent in cattle ; rarely observed in sheep and goats. |
| General condition | Weight loss leading to cachexia generalized weakness |
| Production | Decrease in milk and meat production · wool production disorders in sheep |
| Reproduction | Reduced fertility · repeated returns to heat · interval calving-elongated calving |
| Associated infections | Increased susceptibility to other infectious diseases : mastitis, metritis |
| Other signs | Anemia in goats · submandibular edema (hypoproteinemia) |
| Misleading signs | Normal appetite · little or no fever — the animal loses weight while it eats |
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Lesions at autopsy
- Granulomatous enteritis
- Congested and edematous intestinal mucosa
- Regional lymphadenitis
Weight loss and chronic diarrhea are not specific to any disease. Several affections give the same picture as paratuberculosis, and the reverse is just as true : many animals with paratuberculosis are first treated for other thing. The veterinarian therefore compares the hypotheses with each other.
Other causes to consider :
- In adult cattle — digestive parasitism (strongles, paramphistomes, great fluke), imbalance of the ration and acidosis, deficiencies (copper, cobalt, selenium), salmonellosis, BVD / mucous membrane disease, traumatic reticuloperitonitis, tumors and leukosis, renal failure or hepatic.
- In small ruminants — digestive parasitism, poor condition dental, undernutrition, deficiencies, chronic diseases with a “ death ” appearance (visna-maedi in sheep, CAEV in goats), pulmonary adenocarcinoma.
Which points towards paratuberculosis : an animal adult — the signs do not appear in young animals, even if infected — who gradually loses weight while maintaining an appetite, without fever, with diarrhea without blood or mucus, which does not respond to treatment antiparasitics or usual treatments. The signal is even more strong if other animals in the herd have already been culled for weight loss left without explanation : this is the most frequent reason for discovery of illness.
No clinical examination makes it possible to decide : only a laboratory test makes the difference. In a herd where the question arises, paratuberculosis deserves to be actively sought rather than discarded by default.
Once symptoms appear, the outcome is always fatal : there is no treatment. Everything therefore plays out upstream — on the prevention and early detection.
7. Diagnosis : which method to choose ?
Four approaches coexist, with very different compromises between speed, cost and precision. The choice depends on the chosen objective : group screening, confirmation individual, or monitoring of an already vaccinated herd.
| Method | Serum/milk serology (ELISA) | Fecal or environmental PCR | Fecal culture | Culture + PCR |
|---|---|---|---|---|
| Item searched | Anti-MAP antibodies | DNA of the bacteria, searched for in feces or in a environmental sampling. Up to 5 animals per mixture analysis, depending on the laboratory. | Visible presence of bacteria | 42 days of incubation, then PCR |
| Benefits |
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| Disadvantages |
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| Price order | a few euros per animal mixed less than 10 € individually |
approximately 40 € individually approximately 10 € per animal in mixed feces (up to 5 animals) |
— | a few dozen euros for a batch of animals |
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Orders of magnitude 2026, given for purely indicative purposes : the Prices vary greatly depending on the laboratory, volume and region. Request a quote from your analysis laboratory.
The feces are incubated 42 days in a specific environment of mycobacteria : we add mycobactin, a growth factor which MAP absolutely needs to grow, as well as an antibiotic and an antifungal to eliminate everything else. At 42 days, a PCR is carried out. We then do not notice that living bacteria — that’s the whole point of the method.
An animal whose test is negative is not necessarily healthy. The sensitivity of the test used must be taken into account, and an animal in phase silent escapes detection.
Two limits to know before taking samples[6] : antibodies appearing late, ELISA is therefore not recommended on animals under 18 months ; and fecal PCR only detects animals excretors, with reliability limited by the heterogeneous distribution of bacteria in feces — hence the interest in repeating the samples.
Because the tests do not see animals in the silent phase, the moment of the sample counts as much as the method. Four situations justify actively look for paratuberculosis :
- Before any animal introduction — this is the first door entry of the disease into a disease-free herd
- In front of an adult who is losing weight without obvious cause, or diarrhea chronic that does not respond to usual treatments
- On adults, from 24 months : this is the age from of which serological screening has real value
- Repeatedly — a single campaign always underestimates the level of infection. Annual screening of the adult herd, as part of a plan followed by the veterinarian and the GDS, gives a much fairer image
The precise schedule (which animals, how often, with which test) is defined with your veterinarian, depending on the objective : confirm a case, qualify the herd, or manage sanitation.
There does not exist no treatment. The objective is therefore not to treat the affected animal, but break contamination of the rest of the herd. Three levers, to be put in place with your veterinarian.
- 1. Take out the clinical cases. A sick animal excretes massively : it contaminates its congeners, buildings and pastures. He is isolated, then reformed as a priority — the calendar is decide on a case by case basis, in consultation between the breeder and the veterinarian, depending on the value of the animal and the organization of breeding. His descendants are not kept for renewal.
- 2. Screen then reform (“ test and cull ”). The case visible hides 15 to 25 others. Regular screening of the herd allows to identify infected animals and, above all, the excretors, to target reforms — starting with the most contaminating ones. At the same time, health measures (protection of young, colostrum, manure, pastures) are reinforced : without them, screening-reform alone is not enough never.
- 3. Consider vaccination. She doesn’t cure animals yet reached, but she greatly reduces excretion and losses of production, therefore the infection pressure in breeding. Economically, she becomes profitable from 1 to 3 % of infected animals depending on the sector — a threshold reached much more often than we don’t imagine it. She is regulated and falls under the veterinary prescription (see below).
The first reflex remains the same in all cases : call your veterinarian. He makes the diagnosis, then it’s in consultation between the veterinarian, the breeder and the GDS what is the strategy to adopt — rate of screening, order of reforms, priority health measures — depending on of context specific to breeding : level of infection, conduct of herd, objectives and means of the operation.
What happens
New diagnostic tests are currently being researched and validated : bacteriophage detection, identification of biomarkers[9].
8. Prophylaxis : the 5 pillars[2]
There is no treatment : prevention remains the best — and only — solution. The five pillars below are complete ; none is enough alone.
1 Environmental hygiene (pasture)
- Lime or calcium amendments on acidic soils
- Prevent young animals’s access touncontrolled water : ponds, streams
- Separate young animals and adults on the pastures
- Limit access of wild ruminants to pastures and food stocks (fences, silos and protected fodder)
- Contaminated pasture : no ruminants on it for at least 1 year
2 Building hygiene
- Clean and dry floors — mechanical scraping of manure and slurry, then high pressure cleaning with hot water, and above all complete drying
- Don’t rely on bleach alone : MAP resists most common disinfectants, and even survives chlorination of water drink. Choose a tuberculocidal disinfectant — for example sodium hydroxide (soda), chlorine dioxide or acid peracetic at 0.35 % — knowing thatnone acts on a surface still loaded with organic matter[4]
- Immediate isolation of clinical animals, and priority reform
- If the herd is infected : immediate separation of dairy cow/calf
- When breastfeeding : wear a particular attention to the hygiene of udders
3 Manure management
- No spreading on the plots of young animals under one year old
- Storage 6 months minimum before spreading ; composting recommended
- Equipment cleaning in contact
4 Everyday animals
Priority : protecting young animals
- March forward : during the day, keep busy first of all young, then older animals — never the other way around. We thus avoid carry the bacteria from adults to young animals, via hands, boots and material
- Limit contact with adults, especially if the infection of the herd is proven
- Separate buildings and pastures
- Colostrum and milk controlled. The calf receives colostrum clean, taken from a cleaned udder, and from a healthy mother. Colostrum is discarded from questionable, sick or unknown status females, and we avoid the colostrum and milk mixture : a single animal infected contaminates the entire batch
- Maximum sun exposure pastures
- Raised Troughs and Drinkers in stables, to avoid that they are soiled by feces ; keep young animals away from adults up to at least a year[10]
- Do not keep the descendants of mothers for renewal infected — intrauterine transmission is demonstrated, and even more so more common than the mother is advanced in the disease[11]. These young animals are oriented towards fattening or culling, not kept as future breeding
And on a herd scale
- Securing purchases — this is the first gateway to illness. Two additional checks : request the health status of the selling livestock (livestock guarantee to low risk, screening history) and test the animal by ELISA before its introduction. Attention : each one taken in isolation has its limits — a negative ELISA does not prove that an animal is healthy, since it can be in silent phase. A healthy animal from a herd with status known remains the best buy
- Adapted diet, to avoid deficiencies and declines immunity
- Antiparasitics : control parasitism, which weighs on immunity
- There Sensitivity varies between breeds and individuals[2] : a part resistance is heritable. No genetic index is currently disseminated in routine in France, but it is a medium-term avenue of work
5 Vaccination
Vaccination constitutes the fifth pillar in the fight against paratuberculosis. Recent scientific journals describe it as one of the most effective and practicable measures for reduce bacterial shedding and losses in a herd infected[9].
It does not replace the four other pillars : it slows down significantly the circulation of the bacteria without making the infection disappear, and has meaning only associated with rigorous health prophylaxis.
The paratuberculosis vaccines currently on the European market do not require that one single dose for life. For more information on this subject, consult your veterinarian.
The framework is not the same depending on the species, because it arises from the regulation tuberculosis : anti-paratuberculosis vaccination can interfere with bovine tuberculosis testing, especially with thesimple intradermal tuberculin.
- Cattle and goats — upon exemption. The decree of October 8, 2021 prohibits it in principle, but its section 39 allows the departmental director in charge of population protection (DDPP) to authorize it, “ on written request ” of owner or operator, under two cumulative conditions[15] : no lesion suggestive of tuberculosis observed at post-mortem inspection or necropsy on a bovine or goat of exploitation during the last twelve months, And laboratory tests which revealed the infection paratuberculosis in the herd.
- Sheep — free. Sheep are not covered by this ban : vaccination is simply a matter of veterinarian’s prescription, without contacting the DDPP.
Practical modalities — indications, protocols by species, age of vaccination, are detailed in our veterinary area, accessible to professionals.
Frequently asked questions about paratuberculosis
What is paratuberculosis (Johne’s disease) ?
Paratuberculosis, or Johne’s disease, is an infectious and contagious disease ruminants caused by bacteria Mycobacterium avium subspecies paratuberculosis (MAP). It affects cattle, sheep and goats, as well as wild ruminants. It is a disease with worldwide distribution, with chronic evolution and very long incubation.
How is paratuberculosis transmitted?
Mainly by fecal-oral route, via food, soil or water contaminated by feces. Infection of the calf by milk or colostrum contaminated is a well-documented pathway – mixed milk amplifies it – and the transplacental transmission is demonstrated. Calves under 6 months of age are the most sensitive and become infected especially during feeding, on soiled teats.
What are the symptoms of paratuberculosis in cows ?
Constant to intermittent diarrhea, gradual weight loss until cachexia, generalized weakness and decreased milk and milk production meat. Two signs are misleading : the appetite remains normal and there is no usually no fever. In sheep and goats, diarrhea is rarely observed.
Why is paratuberculosis called “ iceberg disease ” ?
Because the symptoms appear late and not systematically : a single clinically ill animal means 15 to 25 other infected animals without symptoms in the herd, depending on the level of infection of the herd. These animals already excrete the bacteria and see their production decreases, but these losses go unnoticed.
Is there a treatment for paratuberculosis ?
No. There is no treatment, and the disease is always fatal once the symptoms reported. The fight is based exclusively on prophylaxis : hygiene of pastures and buildings, manure management, protection of young animals and vaccination.
Does a negative test mean the animal is healthy ?
No. During the silent phase, which often lasts several years, the animal is infected but does not excrete or sheds too little to be detected, and remains seronegative : it escapes testing. The sensitivity of the test used must always be taken into account, and the results must be repeated and interpreted at the herd level.
How long does the bacteria survive in the environment ?
Very long : up to a year and more on certain pastures, up to almost two years in water, and 8 to 11 months in cattle feces. These are maximum durations : the bacteria does not multiply outside an animal and its infective power decreases clearly within a few months, even more quickly if the plot is sunny. On the contrary, moist and acidic soils, cold and shade preserve it. This is why a contaminated pasture must no longer receive ruminants for at least a year.
Is paratuberculosis a notifiable disease ?
No, not in the sense of the French health police : it is neither a health danger first or second category, and it does not entail compulsory slaughter or regulatory restriction of movements. At the European level, it is listed in category E of the animal health law (EU regulation 2016/429), that is to say a disease subject to surveillance. In France, the struggle is voluntary and organized by the Health Defense Groups (GDS), with a guarantee of low-risk livestock and control plans through screening. There is no no national plan for small ruminants, but some GDS offer plans premises.
Helping you with paratuberculosis
Melchior Santé Animale supports veterinarians and breeders in the prevention of infectious diseases of ruminants. Our teams are at your disposal.
Scientific sources
Note calls [1] placed in the text refer to this list : click on the number to reach the reference.
- Garcia A.B., Shalloo L. « Invited Review: The economic impact and control of paratuberculosis in cattle ”. Journal of Dairy Science, flight. 98, no. 8, August 2015, p. 5019-5039. doi:10.3168/jds.2014-9241
- “ Paratuberculosis ”. Preventing with Experts. preventingwithexperts.com
- Elguezabal N. et al. « Estimate of Mycobacterium avium subsp. paratuberculosis growth parameters ”. Applied and Environmental Microbiology, flight. 77, no. 24, December 2011, p. 8615-8624. doi:10.1128/AEM.05818-11
- “ Paratuberculosis (Johne’s Disease) ”. Center for Food Security and Public Health, Iowa State University, data sheet. cfsph.iastate.edu
- Regulation (EU) 2016/429 of March 9, 2016 (“ animal health law ”) and Implementing Regulation (EU) 2018/1882 of December 3, 2018 establishing the categorization listed diseases. eur-lex.europa.eu
- Handles. “ Paratuberculosis ”, sheet “ animal diseases ”, September 2023. The Ploufragan-Plouzané-Niort laboratory is a national laboratory reference for paratuberculosis (GDS France and OMSA mandates). anses.fr
- “ Paratuberculosis ”, brochure and calculation note (May 2026), Melchior Animal Health and Cristal Network — costing established from references French technical-economic companies (IDELE, INOSYS Livestock Networks, GDS) and the international literature. melchior-santeanimale.fr
- Johne’s Information Center, University of Wisconsin. johnes.org
- Arrazuria R., Alonso-Hearn M., Juste R. et al. « Advances in paratuberculosis research and control: a comprehensive expert review ». BMC Veterinary Research, 2026. doi:10.1186/s12917-026-05717-z
- “ Paratuberculosis ”, general information sheet on diseases. World Organization for Animal Health (WHOA). woah.org
- Whittington R.J., Windsor P.A. « In utero infection of cattle with Mycobacterium avium subsp. paratuberculosis: a critical review and meta-analysis ”. The Veterinary Journal, 2009;179(1):60-69. doi:10.1016/j.tvjl.2007.08.023
- Nielsen S.S., Toft N. « A review of prevalences of paratuberculosis in farmed animals in Europe ”. Preventive Veterinary Medicine, 2009;88(1):1-14. doi:10.1016/j.prevetmed.2008.07.003
- Attili A.R. et al. « Ovine paratuberculosis: seroprevalence study in dairy flocks reared in the Marche region, Italy ». Veterinary Medicine International, 2011;2011:782875. doi:10.4061/2011/782875
- Mercier P. et al. « Paratuberculosis in French dairy goat herds ». Veterinary Record, 2010;167(11):412-415.
- Order of October 8, 2021 relating to health police measures applicable to bovine tuberculosis, section 39 — derogation granted by the departmental director in charge of population protection for anti-paratuberculosis vaccination. legifrance.gouv.fr
- Ottardi M. et al. « Seroprevalence of Mycobacterium avium subsp. paratuberculosis in Swiss dairy herds and risk factors for a positive herd status and within-herd prevalence ”. Frontiers in Veterinary Science, 2024;11:1409694. doi:10.3389/fvets.2024.1409694
- Di Marco Lo Presti V. et al. « Large-scale serological survey we Mycobacterium avium subsp. paratuberculosis infection in sheep and goat herds in Sicily, Southern Italy ». Frontiers in Veterinary Science, 2024;11:1334036. doi:10.3389/fvets.2024.1334036
This sheet is a scientific information document intended for
breeders and animal health professionals. It neither constitutes a
diagnosis, nor a prescription. Any suspicion of paratuberculosis should be
confirmed by your veterinarian, the only one authorized to establish a diagnosis and
define a control plan adapted to your farm.
Sheet written by the Melchior Santé Animale technical team · Updated August 19, 2026.
Clinical photographs and micrographs : Johne’s Information Center,
University of Wisconsin —
johnes.org/johnes-disease-a-to-z.
Icons : Delapouite, Lorc, Skoll, sbed, Caro Asercion, Lord Berandas —
game-icons.net,
license CC BY 3.0.
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