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Ruminal acidosis of sheep
The rumen is a reservoir populated by microbes that digest forage. These microbes work in a low-acid environment and take time to adapt to a change in food. When a sheep swallows a large quantity of cereal, bread or concentrate all at once,...
What is it?
The rumen is a reservoir populated by microbes that digest forage. These microbes work in a low-acid environment and take time to adapt to a change in food.
When a sheep swallows a large quantity of cereal, bread or concentrate all at once, the acid-producing microbes take over. The rumen suddenly acidifies, the useful flora dies, digestion stops.
Acidity draws water from the body towards the rumen: the animal becomes dehydrated from the inside, while poisoning itself.
Key point
Accidental access to grain is an emergency even if the animals still appear normal. Call the veterinarian as soon as you discover it: treating before the signs saves animals that are never caught afterwards.
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:
Acute form, a few hours to a day after the excess: the animal stops eating and ruminating.
The left flank is swollen, the rumen no longer moves; by shaking it you can hear the sound of liquid.
Grinding of teeth, arched back, kicks towards the stomach: pain.
Profuse diarrhea, pale, foamy, sour-smelling, often with visible whole grains.
Rapid dehydration: sunken eyes, skin that remains wrinkled, dry nose.
Unsteady gait, animal that staggers then lies down and never gets up again.
Rapid breathing, temperature often normal or low despite gravity.
Possible death within one to two days in massive cases.
Discreet form: irregular appetite, changing soft droppings, poor growth, animals limping and walking on heels, dull coat.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
Accidental access to a stock: ripped bag, open silo door, poorly closed grain reserve. It is the most common cause of serious accidents, and it often affects several animals at the same time.
Too rapid increase in the proportion of concentrate during fattening or at the end of gestation.
Finely ground or flattened grains, which ferment much faster than whole grain.
Lack of long fiber in the ration: without fodder, the animal ruminates little and its saliva no longer buffers the acidity.
Irregular meals or single distribution: hungry animals rush to the concentrate.
Insufficient space at the trough, which leaves dominants eating too much at once.
Return to the trough after fasting, transportation or illness.
Lambs and fattening animals receiving plenty of concentrate.
Food transitions too fast.
Grain storage accessible to animals.
Ration without quality fodder freely available.
Dominant animals in a lot where space at the trough is limited.
Fattening period before the holidays, where rations are pushed quickly.
Diagnosis and care
Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.
Call the veterinarian immediately, including before signs appear if you notice that a batch has had access to grain: treating before the crisis sets in changes everything.
The veterinarian assesses the general condition, dehydration, the condition of the rumen, and can analyze the rumen fluid to measure its acidity.
A blood test assesses the general impact.
It estimates the quantity ingested and the number of animals concerned to sort those which must be treated as a priority.
He also looks for complications: foot damage, liver damage, abortion in pregnant females.
Treatment
This is an emergency whose treatment is up to the veterinarian.
The principle is to correct acidity, rehydrate the animal and support circulation. Depending on the severity and the number of animals, the veterinarian can empty or rinse the rumen, administer neutralizing products, administer IV fluids, and use anti-inflammatories.
The products and quantities are his decision: oral traditional remedies administered by bottle pass the liquid into the lungs of a weakened animal and kill more than they cure.
During convalescence, only good quality hay and water are given, without concentrate, until the veterinarian authorizes recovery.
The rumen takes days to repopulate; the veterinarian can encourage this recovery by transferring rumen fluid taken from a healthy animal.
All animals in the exposed lot must be monitored, even those which appear normal: the signs may appear with a delay.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Close stocks. An accessible grain store is an accident waiting to happen: most serious cases come from a ripped bag or a poorly closed door.
Any increase in concentrate is done gradually, over several days, never all at once.
Always quality fodder available, distributed before the concentrate: the long fiber makes you ruminate and the saliva protects the rumen.
Split concentrate distributions into several meals rather than just one.
Provide enough space at the trough for all the animals to eat at the same time, which avoids gluttony by the dominants.
Prefer whole or coarsely crushed grains to very fine flours when possible.
After fasting, transport or illness, resume feeding gently, starting with fodder.
Clean water at all times.
Possible complications
Inflammatory disease of the feet, which sometimes makes animals lame weeks later: this is a classic and costly after-effect.
Inflammation of the rumen wall, then liver abscess.
Fungal infections of the rumen wall in the following days, often fatal.
Abortion in pregnant females.
Sustainable decline in growth and production.
Death in one to two days in massive forms.
When to see a veterinarian
Your animals have had access to a stock of grain or concentrate: call without waiting for the signs to appear.
A sheep stops eating and ruminating with a swollen left flank.
Profuse diarrhea with a sour odor, with visible grains.
Grinding of teeth, arched back, staggering animal.
Lying animal that does not get up: emergency.
Lameness appears in the lot a few weeks after overeating: report it, the link is direct.
Prognosis
Good when the veterinarian intervenes in the first hours and the quantity ingested is moderate.
Reserved for dark in an animal already lying down, very dehydrated or which has ingested a large quantity.
Even after recovery, after-effects are common: lameness, slowed growth, liver abscesses discovered during slaughter.
The discreet shape does not kill but is expensive in performance; it is corrected entirely by the ration.
Frequently asked questions
My sheep tore open a bag of barley last night and they are fine this morning: should I be worried?
Yes. The signs often appear after several hours, and it is precisely before their appearance that intervention is most effective. Call the veterinarian, indicating the approximate quantity swallowed and the number of animals affected.
Can I give baking soda or a home remedy while waiting?
Do not administer anything by mouth without advice. A weakened animal swallows poorly and liquid can pass into the lungs. Remove access to the grain, leave hay and water, and follow the veterinarian's instructions.
Why are my lambs lame weeks after too much grain?
Acidosis causes inflammation of the feet which manifests itself with a delay. This is a well-known after-effect: when lameness appears in a fattening flock, the ration must be reviewed as a priority.
How long does it take to increase concentrate?
It takes several days for the rumen flora to adapt, and the increase should be gradual with forage always available. The exact rate depends on the starting ration and the category of animals: have it established by your veterinarian or technician.
References
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
EFSA — Autorité européenne de sécurité des aliments
Content reviewed by the TunisieVet editorial team · Updated 09 August 2026
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