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Obstructive urolithiasis of rams
Crystals form in the urine and clump together into stones. In females, the urinary tract is wide and stones pass most often. In the male, it is long, narrow and elbowed, and ends in a very thin appendage at the end of the sheath: the stones...
What is it?
Crystals form in the urine and clump together into stones. In females, the urinary tract is wide and stones pass most often. In the male, it is long, narrow and elbowed, and ends in a very thin appendage at the end of the sheath: the stones are blocked there.
Urine no longer comes out. The bladder fills, distends, and eventually ruptures, or the urinary tract gives way under the pressure and urine seeps under the skin of the stomach.
It is one of the most common emergencies in rams, goats, lambs and male kids, especially those fattened with a lot of cereals. A male who pushes without urinating must be seen immediately: every hour counts.
Key point
Absolute life-threatening emergency. A male that pushes without urinating, scratches the ground and grinds its teeth should be seen immediately, day or night. Waiting one night most often means losing the animal.
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 male isolates himself, remains standing with his back rounded, his tail wagging, and pushes as if he wanted to urinate without anything coming out, or only a few drops sometimes tinged with blood.
He scratches the ground, stomps, lies down and gets up again, kicks towards his stomach.
Grinding teeth: this is a sign of intense pain in sheep, it should never be neglected.
Whitish, sandy crystals may be visible on the sheath hairs.
He stops eating and ruminating, becomes depressed, breathes quickly.
Many breeders first believe it is constipation, because the animal is pushing: this is the most frequent error and causes the decisive hours to be lost.
When the urinary tract ruptures, a soft, cold swelling appears under the belly and between the hind legs; the pain sometimes decreases, giving a false impression of improvement.
When the bladder ruptures, the abdomen becomes distended, the animal sags, becomes very despondent and stops growing.
When to consult without delay
This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.
Causes and risk factors
A mineral imbalance in the ration promotes the formation of crystals. Rations rich in cereals provide a lot of phosphorus and magnesium compared to calcium; this imbalance is the best recognized factor in fattened males.
Insufficient watering concentrates urine and facilitates crystallization: dirty water, frozen water trough or too far away, brackish water refused by the animals, insufficient number of water troughs for the flock.
Certain naturally highly mineralized waters and certain plants rich in oxalates or silica increase the risk depending on the region.
Very early castration prevents the complete development of the urinary tract, which remains narrower throughout life: males castrated young are the most exposed.
A urinary infection or urine with altered acidity can also promote the formation of stones.
Being a male, especially neutered early.
Fattening lambs and kids receiving a lot of concentrate and little fodder.
Breeding rams fed like fattening animals outside the fighting season.
Limited drinking, cold, dirty, frozen water, or too few water points.
Cold season, when animals spontaneously drink less.
Mineral ration not suitable for small male ruminants.
History of urinary episode in the same animal.
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: the veterinarian must be called as soon as there is suspicion, without waiting to see if it goes away.
He confirms the obstruction by clinical examination, palpation of the abdomen and examination of the sheath, and looks for a rupture of the bladder or urinary tract.
An ultrasound, when available, specifies the condition of the bladder and the presence of fluid in the abdomen.
A blood test assesses the impact on the kidneys and the imbalances that accompany retention.
The veterinarian also assesses the value of the animal and the age of the signs to guide the decision: treatment, surgery or, for a fattening animal, immediate stamping out rather than prolonged agony.
He then examines the rest of the group: the other males receive the same ration and are exposed to the same risk.
Treatment
No home remedy unblocks a blocked male. Do not force the animal to drink, do not massage the belly, do not give anything by mouth without warning: these actions waste time and can precipitate rupture of the bladder.
Depending on the location of the blockage and the condition of the animal, the veterinarian can remove the thin appendix located at the end of the sheath, which is the most common point of blockage, under local anesthesia.
It uses medications to relax the urinary tract and calm pain and inflammation, and corrects general imbalances through infusion.
When the blockage is higher, or when the bladder or duct is ruptured, only surgical intervention can save the animal. It is possible for a valuable breeder or a pet, more rarely for a lamb for fattening.
Recurrences are frequent as long as the ration and watering have not been corrected: treatment never eliminates the need to review behavior.
Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.
Prevention
Permanent access to clean water is the first measure, and by far the most effective: diluted urine forms much fewer stones. Multiply the water points, clean them, protect them from frost and check that they really work every day.
Balance the ration with the veterinarian or technician: favor forage, limit the proportion of cereals in males, and correct the balance between calcium and phosphorus. This balance is the recognized lever of prevention, but it is calculated on the actual ration: it is not copied from one breeding to another.
Use a mineral designed for male sheep, never a mineral designed for another species or another category of animals.
A suitable salt stone encourages animals to drink more, provided water is constantly available.
Urinary acidifiers exist: they can only be used on prescription and with monitoring, because if used incorrectly they are dangerous.
Delay the castration of males when breeding management allows it, to allow the urinary tract to develop.
Monitor fattening males daily: seeing each animal urinate is the best control possible.
Possible complications
Rupture of the urinary tract, with infiltration of urine under the skin of the abdomen.
Bladder rupture and accumulation of urine in the abdomen.
Poisoning of the body by waste that the kidneys no longer eliminate.
Permanent damage to the kidneys.
Peritonitis and generalized infection.
Death in one to three days in the absence of intervention.
Loss of reproductive function after certain surgical procedures.
When to see a veterinarian
A male pushes without urinating, or only emits a few drops: call immediately, it is a life-threatening emergency.
He scratches the ground, stomps, kicks towards his stomach.
He grinds his teeth: it is a sign of intense pain.
Blood or crystals are visible at the end of the sheath.
Their stomach swells, or a soft swelling appears under the stomach.
He has stopped eating and remains in bed: don't wait until the next day.
You suspect constipation in a growing male: have it checked, confusion is common and costs the animal's life.
Prognosis
Good when the obstruction is taken in the very first hours and the blockage is at the end of the sheath.
Reserved as soon as the animal has been stranded for more than a day.
Dark after rupture of the bladder or urinary tract, even after surgery.
Recurrences are frequent if the ration and watering do not change: the real cure requires correcting the breeding behavior.
Frequently asked questions
My lamb is growing: it's not just constipation?
In a male, you should always think about urinary blockage first. Both look similar, but one waits and the other kills within hours. Doubt is resolved by a veterinary examination, not by waiting.
Why only males?
The male's urinary tract is long, narrow and bent, and ends in a very thin appendage where the stones get stuck. In the female, it is short and wide: the same crystals pass without blocking.
Should I stop giving my fattening lambs cereals?
Not necessarily, but their share must be controlled and the mineral balance of the ration corrected, always with fodder and water at will. It is the imbalance in the ration, not the cereal itself, that creates the problem. Have the ration calculated rather than adjusting it by guesswork.
Can a cured animal start again?
Yes, and it is common until the cause is corrected. After an episode, reviewing the ration and watering of the entire flock is essential, because other males are exposed to the same risk.
References
AVMA — American Veterinary Medical Association
FAO — Organisation des Nations unies pour l'alimentation et l'agriculture
Content reviewed by the TunisieVet editorial team · Updated 09 August 2026
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