Home › Animalia › Animal health › Animal diseases › Wet mouth syndrome
Wet mouth syndrome
Wet mouth syndrome strikes lambs in their very first days of life, most often before three days of age. Common environmental bacteria, present en masse in soiled lambing litter, are swallowed by a lamb which has not yet received enough colo...
What is it?
Wet mouth syndrome strikes lambs in their very first days of life, most often before three days of age. Common environmental bacteria, present en masse in soiled lambing litter, are swallowed by a lamb which has not yet received enough colostrum. As nothing stops them, they proliferate in an immature digestive tract and release toxins which pass into the blood. The lamb then becomes poisoned from the inside. His intestine becomes paralyzed, gas accumulates, he stops sucking and his mouth fills with cold, stringy saliva which wets the entire muzzle: it is this very characteristic sign which gave its name to the disease. The name misleads the breeder, because it suggests a mouth problem when the problem is general and serious. A lamb with a wet mouth is a lamb dying of blood poisoning: it's an emergency of the same minute, not the next morning. It is also, and this is the good news, one of the most preventable lambing diseases: it is almost always a sign that a lamb did not drink quickly enough, or that it was born in a place that was too dirty.
Key point
A drooling lamb with a swollen belly is an immediate emergency, not a temporary inconvenience. Above all, do not give him milk: call the veterinarian.
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:
The lamb no longer suckles, loses interest in the udder and stays away from its mother.
Abundant, cold, stringy saliva, which wets the muzzle, chin and neck wool. The mouth feels cold when you put your finger in it, when it should be lukewarm.
Rapid decline: the lamb remains lying down, head on its side, gets up with difficulty or cannot get up at all.
Swollen, tense belly, which resonates like a drum or which makes a sound of liquid when the lamb is gently lifted: breeders speak of a clicking belly.
Grinding teeth and signs of abdominal pain.
Absence of droppings: the first meconium is not evacuated, or nothing has come out for hours.
Rapid dehydration, body getting cold, pale or grayish gums.
Dead in a few hours if nothing is done.
Diarrhea is generally absent at the beginning: do not look for it as a warning sign, it arrives too late.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Environmental bacteria, mainly colibacilli, are ingested by the lamb in the very first hours of life, when it searches and licks everything around it in search of the udder.
A lamb that has not received enough colostrum has no defense: colostrum is the only source of antibodies for the newborn, who is born without protection, and it also acts as a protective dressing for the intestine.
Bacteria multiply in a still inert intestine, produce toxins, and the intestine stops functioning completely. Gases and fluids build up, the toxin passes into the blood and the lamb goes into shock.
Everything that delays the first feeding contributes to this: weak lamb, difficult lambing, ewe without milk, ewe which refuses its lamb, multiple litters where the smallest is preceded, cold which exhausts the lamb before it has found the udder.
Anything that increases the dose of bacteria also contributes: wet and loaded litter, lambing pens reused without cleaning, dirty udders, high density of lambings in little space.
Insufficient or too late colostrum intake: this is the central factor.
Lambs from multiple litters, low weight lambs, lambs from difficult lambing.
Thin ewes, poorly nourished at the end of gestation, or whose udder produces little.
Ewe whose udder is dirty or whose teats are blocked by a plug of wax that has not been removed.
Reused lambing crates without cleaning or fresh mulching, moist litter, high density.
Second half of the lambing season, when the microbial load in the building is at its peak.
Cold, wet weather, which exhausts the lamb before the first feeding.
Orphaned or bottle-raised lambs in approximately hygienic conditions.
Transmission
This is not a lamb-to-lamb contagion: each one becomes infected from the environment in which it is born.
But the buildup of bacteria in a lambing barn increases as the season progresses. The first born lambs are born in a relatively clean place; those at the end of the campaign are born into a much busier environment, and they are the ones who pay.
This is why cases often multiply in the second half of the lambing season, without the breeder having changed anything.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
The veterinarian recognizes the picture by cold salivation, a distended stomach and the absence of droppings in a lamb a few hours or a few days old.
He palpates the abdomen, looks for accumulation of liquid and gas, takes the temperature, assesses the state of dehydration and the state of shock.
He excludes the other emergencies of very young lambs which are very similar: hypothermia of the newborn, diarrhea of lambs, infection of the navel, generalized infection by the navel, and the absence of an anal orifice, which also gives a swollen belly without droppings. These situations do not have the same behavior to follow.
He checks the mother's udder and the lamb's real ability to suckle.
Faced with several cases in the same building, he examines the lambing management as a whole: this is where the solution comes into play.
Treatment
It's a veterinary emergency. Every hour counts and a lamb that appears lost can still be saved if caught early.
Treatment generally combines a suitable antibiotic and rehydration, on prescription. The veterinarian decides on the route of administration: in a lamb in shock, the intestine no longer absorbs anything and liquids must be administered other than through the mouth.
Reheating the lamb is essential above all else if it is cold, but a reheated lamb is not a cured lamb: the toxin is still circulating.
Means of emptying the digestive tract and supportive care may be added by the veterinarian.
Do not give milk to a lamb with a swollen belly and a wet mouth: its intestine is blocked, milk accumulates there and makes the situation worse. This mistake, made with the best of intentions, kills lambs every season.
Do not use leftover antibiotics from another campaign or a product recommended for coffee: the molecules that can be used in a two-day-old lamb and the route of administration fall within the prescription.
As soon as a first case is treated, attention must be focused on the unborn lambs: it is the organization of lambing that must change, without waiting for the next case.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Taking colostrum is the measure that matters more than all others. Every lamb should drink colostrum as soon as possible after birth, and it should be verified that it actually drank, not just assumed that it did. A lamb with a full, plump belly has drunk; a hollow-sided lamb, no.
Immediately help weak lambs, babies from multiple litters and those whose mothers have little milk. The veterinarian will advise how to give colostrum to a lamb that is not suckling and how to maintain a supply of good quality colostrum.
Check that the ewe's teats are permeable: a plug of wax not removed condemns the lamb to fasting next to a full udder.
Feed sheep correctly at the end of pregnancy: the quantity and quality of colostrum directly depend on it.
Clean, disinfect and re-mulch the lambing pens between two ewes, do not allow soiled litter to accumulate, and provide enough pens so as not to lamb in a corridor.
Disinfect the navel of each lamb at birth using the method recommended by the veterinarian: this also protects against other newborn diseases.
Increase vigilance in the second half of the lambing season, even if everything has gone well until then.
If cases continue despite everything, a preventive drug strategy can be discussed with the veterinarian, but it never replaces colostrum and cleanliness.
Vaccination
There is no vaccine specifically against this syndrome.
On the other hand, vaccination of ewes at the end of gestation, discussed with the veterinarian, enriches the colostrum with antibodies against other dangerous diseases of young lambs, notably enterotoxemia and tetanus. It follows the same logic: protecting the lamb by its mother, before its birth.
Possible complications
Died within a few hours, often the same day as the signs appeared.
Surviving lambs that remain puny, take poorly and have difficulty catching up with their littermates.
Secondary infections, particularly of the joints, in lambs poorly protected by colostrum.
Serial losses over the entire end of the lambing campaign when the cause is not corrected.
When to see a veterinarian
A lamb less than three days old is drooling, has a wet and cold nose, and is no longer suckling: call immediately.
His stomach is swollen and tense, he is not passing poop.
He remains lying with his head on his side and does not get up when you approach.
He grinds his teeth or seems to have stomach pain.
Several lambs show these signs in the same week: lambing management should be reviewed with the veterinarian without delay.
A lamb born at night clearly did not drink in the early morning: this is already a situation that needs to be addressed, even before it becomes ill.
Prognosis
Taken in the very first hours, with veterinary treatment and appropriate rehydration, some lambs survive.
Once the belly is very distended and the lamb is cold and lying down, the prognosis becomes poor despite care.
At the flock level, the prognosis is excellent: it is a breeding disease, and farms that secure colostrum and clean lambing pens see it practically disappear.
Frequently asked questions
My lamb is drooling a lot, did he choke on milk?
This is what we often believe, and it is a costly mistake. In a lamb a few days old which is no longer suckling, cold and abundant saliva almost always accompanies blood poisoning from the intestine. You have to call the vet within the hour, not wait to see.
How long do I have to give colostrum?
The sooner the better: the capacity of the lamb's intestine to absorb antibodies decreases very quickly over the first few hours and then disappears. A lamb that has not drunk in the first hours of its life is a lamb at risk, even if it appears vigorous. Ask the vet how to stock up on colostrum.
Why do cases increase at the end of the lambing season?
Because the amount of bacteria in the building increases with each lambing. The last lambs are born in a much busier environment than the first. Cleaning, disinfecting and re-mulching the pens between two sheep breaks this increase in load.
Can I give him milk or sugar water while waiting for the vet?
No. In a lamb with a swollen belly, the intestine is paralyzed: everything you pour accumulates there and aggravates the condition. Warm him gently if he is cold, do not force him to drink, and call the veterinarian, who will bring the liquids through a suitable route.
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 veterinarianCategories
Affected 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.
To discover
Related diseases and linked Animalia content.
Rabies
Viral · Vaccine available
Toxoplasmosis
Parasitic
Coccidiosis
Parasitic
Foot-and-mouth disease
Viral · Vaccine available