Home › Animalia › Animal health › Animal diseases › Lamb dysentery
Lamb dysentery
Lamb dysentery is an enterotoxemia that affects lambs in their very first days of life. It is caused by a bacteria from the same group as that of the pulpy kidney, Clostridium perfringens type B. The bacteria multiply in the newborn lamb's...
What is it?
Lamb dysentery is an enterotoxemia that affects lambs in their very first days of life. It is caused by a bacteria from the same group as that of the pulpy kidney, Clostridium perfringens type B. The bacteria multiply in the newborn lamb's intestine and release toxins that destroy the intestinal wall. The intestine bleeds and necroses: hence the name dysentery. It affects vigorous, well-born lambs that suckle well. It is often the strongest lamb in a litter that leaves first. The disease generally appears in lambs born in the middle or end of the lambing period, when the premises have become loaded with microbes. The first born often pass through, the later ones pay for the accumulation. Without vaccination of sheep, losses can be repeated every year in the same sheepfolds, because the spores persist for a long time in the litter and soil.
Key point
Severe disease of lambs a few days old, against which there is practically nothing to do once declared. Everything happens beforehand: vaccination of the ewes during pregnancy and intake of colostrum.
Commonly observed signs
These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.
Related signs — each one links to its page:
Many lambs are simply found dead, without having appeared ill a few hours earlier.
When the disease is seen in time: lamb which suddenly stops suckling, remains lying down, refuses to follow its mother.
Marked abdominal pain: the lamb complains, moans, lies down and gets up, tenses its back, the stomach is tense and painful to the touch.
Watery diarrhea, often reddish brown or frankly bloody, sometimes with mucous debris.
Rapid dehydration, lamb cold to the touch, sticky gums.
Lamb which remains lying on its side and never gets up again before death.
In some cases, the lamb dies before diarrhea even appears: the absence of bloody stools therefore does not rule out the disease.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
The bacteria is present in the environment in the form of very resistant spores, in litter, the floor of the sheepfold, on wool and soiled udders.
The lamb swallows it in the first hours of life, while suckling a dirty udder or licking the litter.
In the intestine of a very young lamb, still immature and rich in milk, the bacteria finds ideal conditions to multiply.
It then produces toxins which destroy the lining of the small intestine, cause bleeding and pass into the blood.
Abundant and irregular feeding, in a lamb which remains for a long time without sucking then suddenly fills up, favors this multiplication.
Lambs born to unvaccinated ewes have no protection in colostrum: this is the determining factor.
Ewes not vaccinated before lambing: this is by far the number one factor.
Lambs born in an overcrowded barn, with damp and old litter, in the middle or at the end of the lambing period.
Soiled udders and hindquarters of sheep, dirty wool around the udder.
Vigorous lambs with large suckers, from very dairy ewes.
Lambs that suckle irregularly, for example when separated and returned to the mother.
Lambs that received little or no colostrum in their first hours of life.
Sheepfolds having already experienced cases in previous years.
Cold and humidity, which push animals to huddle together on loaded litter.
Transmission
The disease is not contagious in the usual sense: the sick lamb does not directly contaminate its neighbors.
Contamination comes from the environment, in particular from soiled litter and udders, where spores accumulate over the lambing period.
The more lambing progresses, the more the spore load increases in the building: lambs born at the end of the campaign are the most exposed.
The spores persist for years in the ground and buildings, and are resistant to most common disinfectants: you cannot rid a sheepfold of this microbe by cleaning alone.
No risk for humans.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
When faced with deaths of newborn lambs, the veterinarian takes stock of the exact age of the affected animals, the time in the lambing campaign, the condition of the litter and the vaccination status of the ewes.
An autopsy, carried out by the veterinarian and quickly after death, is the most decisive examination: the hemorrhagic appearance of the small intestine is very suggestive.
Do not open a corpse yourself: other causes of sudden death exist, some of which pose a risk to humans.
Samples of intestinal contents may be sent to the laboratory to test for toxins.
The veterinarian rules out other causes of diarrhea and mortality in the very first days, in particular classic infectious diarrhea in lambs, septicemia in newborns and hypothermia: the action to be taken is not the same and several can coexist in the same batch.
Treatment
The progression is so rapid that treatment almost always comes too late: most affected lambs die despite treatment.
On a lamb that is still standing, the veterinarian can try supportive treatment: rehydration, warming, antibiotics and anti-inflammatory drugs on prescription, with uncertain results.
Antibody serums exist in certain countries and can be offered to lambs from the same batch that are still healthy; their availability is assessed with the veterinarian.
The useful action concerns future lambs and those that have just been born: cleaning and abundant mulching of the lambing room, separation of batches, shearing or cleaning of soiled wool around the udders, reinforced monitoring of feedings.
In a declared episode, the veterinarian can decide on action at the scale of the lot; this decision is his.
Never administer leftover antibiotics from a previous episode: it is ineffective, it delays the call to the veterinarian and it encourages resistance.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Vaccination of ewes before lambing is the only truly effective measure. It protects the lambs with colostrum during the period when they are vulnerable.
Ensure that each lamb takes colostrum from the first hours of life: without colostrum, the mother's vaccination is of no use to the lamb.
Mulch lambing pens abundantly and frequently, drain between batches, and do not allow litter to become loaded throughout the campaign.
Limit the density in the lambing room, separate ewes that have given birth from waiting ewes.
Shear or clean soiled wool around the udder and hindquarters before lambing.
Avoid lambs going a long time without sucking and then suddenly filling up.
If the sheepfold has already experienced cases, consider that it remains concerned: cleaning is not enough, vaccination of the sheep is essential every year.
Vaccination
The multipurpose clostridial vaccines used in sheep farming cover this form at the same time as other enterotoxemias: a single injection protects against several diseases in the flock.
The logic is that of protection by the mother: the ewe is vaccinated during gestation, she produces antibodies which she transmits to her lamb in the colostrum.
Two conditions must be met for this to work: the ewe must have received its complete primary vaccination then its boosters, and the lamb must actually suck the colostrum in its first hours of life.
A ewe vaccinated for the first time needs several injections before lambing; a ewe already vaccinated in previous years receives a booster before each lambing. The precise schedule is set by the veterinarian.
Vaccinating sheep a few days before giving birth does not give the antibodies time to pass into the colostrum: anticipation is essential.
The protection transmitted runs out after a few weeks; lambs kept for breeding or fattening must then be vaccinated for themselves.
Possible complications
Death of the lamb, most often in less than a day.
Repeated losses throughout the end of the lambing campaign if nothing is corrected.
Surviving lambs which retain a damaged intestine, digest poorly and remain stunted.
Sheep who lose their lamb and remain unproductive in the countryside.
Long-lasting contamination of the building, with reappearance in subsequent years.
When to see a veterinarian
A lamb a few days old is found dead without appearing ill: call the veterinarian and do not open the body.
A newborn lamb suddenly stops sucking, complains and remains lying down.
Brown or bloody liquid stools appear in a lamb less than a week old: it is an emergency.
A lamb's belly is tight and painful to the touch.
Several lambs die in the same room within a few days.
Before the next lambing campaign, if you have already lost lambs like this: the time to act is before lambing, not during.
Prognosis
The individual prognosis is very poor: destruction of the intestine is already established when the signs appear.
The prognosis for the herd, on the other hand, is excellent with the vaccination of the ewes: farms which vaccinate regularly hardly see this disease anymore.
Without vaccination, losses are repeated every year in the same buildings, with worsening at the end of the lambing campaign.
Frequently asked questions
My first lambs were doing well and now I'm losing some: why?
It's very characteristic. Microbes build up in the litter as the lambing season progresses, and lambs born later receive a much heavier load. This does not mean that anything has changed in your behavior: it is the mechanical effect of the accumulation, which the cleaning and vaccination of the sheep corrects.
Is it the same disease as enterotoxemia in fattening lambs?
It's the same family of bacteria, but not the same shape or the same age. Dysentery strikes the newborn with a bleeding intestine; the pulpy kidney strikes the older lamb, growing on a rich ration. Multivalent vaccines cover both, which makes things a lot simpler.
Should we disinfect the sheepfold to get rid of it?
Draining and heavy mulching really reduces the pressure, and it must be done. But the spores of these bacteria are resistant to most common disinfectants and persist in the soil: you do not clean a sheepfold of this microbe. This is why vaccination of sheep remains essential.
Can a lamb that has survived be kept for breeding?
This should be discussed with the veterinarian. A lamb that has had a damaged intestine often digests less well and lags behind its peers. Le garder pour la reproduction est rarement un bon calcul.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
Content reviewed by the TunisieVet editorial team · Updated 11 August 2026
AT A GLANCE
Need a veterinarian?
Find a practitioner near you on TunisieVet, with their specialities, hours and contact details.
Find a veterinarianAffected species
This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.
Thinking of welcoming a pet? Dogs and cats are waiting for a family in Tunisia, and adoption is completely free.
Adoption listingsTo discover
Related diseases and linked Animalia content.
Rabies
Viral · Vaccine available
Toxoplasmosis
Parasitic
Coccidiosis
Parasitic
Foot-and-mouth disease
Viral · Vaccine available