Home › Animalia › Animal health › Animal diseases › Salt poisoning
Salt poisoning
The name of this poisoning is misleading: the problem rarely comes from too much salt, and almost always from a lack of water. A sheep that normally consumes salt but can no longer drink sees the sodium concentrated in its blood and in its...
What is it?
The name of this poisoning is misleading: the problem rarely comes from too much salt, and almost always from a lack of water.
A sheep that normally consumes salt but can no longer drink sees the sodium concentrated in its blood and in its brain. As long as it remains deprived of water, it holds up. It is when he finally drinks, often greedily, that the tragedy occurs: the water rushes into the brain, which swells. The animal convulses and dies.
This is the central trap of this disease: the gesture that seems the most generous, letting a thirsty animal drink as much as it wants, is the one that kills it.
Key point
The danger of this poisoning is not the salt but the return of the water. If you discover a batch that has gone without drinking, do not refill the drinkers as needed: offer small, repeated amounts and call the veterinarian. Letting a thirsty animal drink to its fill causes its brain to swell and kill it.
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:
At the beginning, during deprivation: slaughtered animals, which eat less, crowd around the water point, appear dehydrated.
Intense and noisy thirst as soon as water becomes available again: animals fight to drink and swallow enormous quantities.
Nervous signs then appear, often a few hours after resuming drinking.
Blindness: the animal bumps into walls, barriers, water troughs, no longer recognizes its environment.
Walks aimlessly, in a circle, head pushed against obstacles.
Tremors, staggering gait, animal stumbling.
Repetitive seizures, falling on side, pedaling legs, chewing.
Sometimes diarrhea and abdominal pain.
Animals that remain lying down, in a coma, and die.
Several animals from the same batch are affected at the same time, which clearly distinguishes this poisoning from an individual 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
Water deprivation, whatever the reason: broken drinker, blocked float, blocked or frozen pipe, empty tank, pump stopped, power cut, overturned drinker.
Animals locked up without water: prolonged transport, day of sorting, shearing, vaccination, waiting before a sale or party.
Water refused by animals because it is dirty, too hot, too salty or has a bad taste: they do not drink even though the water is present.
Naturally salty bore water in some areas, which becomes dangerous when it is the only source available.
High consumption of salt, salt blocks or very salty foods without sufficient water nearby.
Newly arrived animals that don't know where to drink or how the water bowl works: this is a common cause and easy to correct.
Dominance in the flock: a few animals monopolize the water point and the weakest do not drink.
Extreme heat, a situation where the sheep's water needs increase significantly.
A single water point for a large lot, or water point difficult to access.
Animals in buildings, entirely dependent on the installation.
Long transports, gatherings, fairs, holiday periods where animals are moved and parked.
Automatic waterers not checked daily.
Areas where borehole water is salty or brackish.
Animals having just arrived on the farm.
Ration rich in salt or salt blocks freely available.
Lambs and weak animals, kept away from the water point by the dominant ones.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
It's an emergency: call the veterinarian before letting the animals drink freely.
The diagnosis is based above all on the context, and the breeder has the decisive information: was there a drinker failure, transport, a day without water. Say it frankly, it completely changes the course of action.
The veterinarian carries out a nervous examination and rules out other causes of blindness and convulsions in sheep: lead, enterotoxemia, deficiencies, infectious brain diseases, whirling disease.
A blood test measures sodium and confirms the diagnosis.
The examination of a dead animal, with brain samples, provides confirmation and helps protect the rest of the batch.
The veterinarian checks the drinking facility and water quality, which is as important as the treatment itself.
Treatment
The absolute, and counterintuitive, rule is not to let a lot deprived of water drink as much as they want. Rehydration must be gradual and supervised by the veterinarian: this is what prevents swelling of the brain.
In practice, as soon as you notice that a flock has remained without water, call the veterinarian before resuming watering, and offer water in small quantities, several times, rather than a full waterer at once.
The veterinarian sets up controlled rehydration, usually by infusion, with treatment of brain swelling and control of seizures.
Affected animals must be placed in a quiet place, in the shade, on thick bedding, protected from injury during attacks. Noise and handling make seizures worse.
No medication should be administered by the breeder on their own initiative.
The rest of the batch is monitored closely for several days, as signs may appear staggered.
Correcting the drinking installation is part of the treatment: without it, the accident will recur.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Check the water every day, without exception, and particularly during hot weather: this is the action that avoids almost all cases.
Provide several water points per lot, accessible to the weakest animals, and at a height suitable for lambs.
Regularly check floats, pipes, pumps and tanks, and provide a reserve in the event of an outage.
Never leave animals locked up without water during sorting, shearing, vaccination or waiting for sale, even for half a day.
Give water during long journeys and upon arrival, making sure everyone drinks.
Clean the drinkers: dirty or too hot water is not drunk, which amounts to not having any.
Have borehole water analyzed in areas where it may be salty, and do not make it the only available source if it is.
Show newly arrived animals the water point and check that they use it.
If a batch remains without water, do not reopen the water trough: ration it and call the veterinarian.
Possible complications
Death from brain swelling, often in several animals from the same batch.
Blindness and permanent nervous after-effects in some of the survivors.
Injuries and fractures during seizures.
Abortions in pregnant females.
Long-lasting production losses in animals that partially recover.
Recurrence of the accident if the watering system is not corrected: this is by far the most frequent complication.
When to see a veterinarian
You discover that a batch has remained without water: call before reestablishing unlimited watering.
Animals bump into each other, turn in circles, or appear blind after drinking heavily.
An animal convulses or remains lying on its side: emergency, call immediately.
Several animals from the same batch present nervous disorders on the same day.
An animal dies suddenly after transport or a day of confinement.
Your animals refuse to drink the available water: the risk is the same as if there was none.
Prognosis
The prognosis is guarded as soon as the convulsions have set in: some of the animals die despite correct care.
Animals identified at the stage of simple water deprivation, before nervous signs, do very well if rehydration is progressive and supervised.
Some survivors remain blind or have permanent behavioral problems.
At the herd level, the prognosis is excellent for prevention: it is a poisoning that should never happen, since it is due to daily monitoring of watering.
Frequently asked questions
My sheep haven't had water for a day, what should I do now?
Do not reopen the water troughs. Offer small amounts of water, several times, and call the veterinarian to arrange rehydration. It is when a thirsty animal drinks freely that its brain swells and it convulses.
I do not give salt to my sheep, does this poisoning concern me?
Yes. The name is confusing: in the vast majority of cases, salt simply comes from normal diet and it is the lack of water that creates the problem. A water trough breakdown is enough, even without a salt block.
The water from my borehole is a little salty, is this dangerous?
It can become so if it is the only source available, especially in high heat, or if the animals drink it little because of its taste. Have it analyzed and talk to the veterinarian: the solution often comes from a complementary source rather than treatment.
My animals bump into walls, is it necessarily the salt?
No. Several sheep diseases cause blindness, including lead poisoning, enterotoxemia and certain deficiencies. It is your story of the farm, in particular a possible episode without water, which will help the veterinarian to make a decision quickly.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
ANSES — Agence nationale de sécurité sanitaire (France)
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
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