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environmental disease Sheep

Chronic copper poisoning

Sheep are the livestock species most sensitive to copper. His liver stores copper almost without limit and does not know how to eliminate it correctly: it accumulates, week after week, without anything being seen. Then, one day, the saturat...

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Definition Signs Causes Diagnosis Treatment Prevention Complications When to see a vet Prognosis FAQ Sources Affected species

What is it?

Then, one day, the saturated liver suddenly releases all the copper into the blood. Red blood cells burst en masse. Within a few hours, the animal turns yellow, urinates port-colored liquid and dies.

It is this discrepancy that deceives everyone: the fault was committed weeks or months earlier, often by giving the sheep a feed or mineral supplement intended for cattle, poultry or pigs. The breeder therefore does not make the connection.

Key point

Sheep are the least copper-tolerant livestock species. A feed or supplement intended for cattle, poultry or pigs, even given for a few weeks, can kill animals several months later, in a single blow, during simple transport. A yellow sheep that urinates dark should have the vet called the same day, and the entire flock should be considered in danger.

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:

Jaundice Dark urine Reduction Loss of appetite Pale mucous membranes Dehydration Stopped ruminating Rapid breathing Lying animal that does not get up Fatigue

During the entire accumulation phase, which lasts weeks or months, there is nothing to see. The animals eat, grow and look healthy.

The crisis begins suddenly: deep depression, animal which isolates itself, refuses to eat, stops ruminating.

Spectacular jaundice within a few hours: the white of the eye, the inside of the lips, the gums and the skin of bare areas take on a distinct yellow tint.

Dark urine, dark red or port wine color: this is the most characteristic sign, the one that should immediately make you think of copper in a sheep.

Mucous membranes first yellow then very pale, the animal emptying itself of its red blood cells.

Rapid breathing, marked thirst, dehydration.

Animal that staggers, lies down and never gets up again.

Death usually occurs within one to three days; some animals are found dead without anything having been noticed.

When a case occurs, other animals from the same batch are already loaded with copper without showing it: this is the most important data in the entire sheet.

When to consult without delay

This list does not replace veterinary advice. It gathers situations that justify a prompt consultation.

Causes and risk factors

Distribution, even occasional but repeated, of a complete feed, a concentrate or a mineral supplement formulated for cattle, calves, pigs or poultry: these products contain quantities of copper perfectly tolerated by these species and dangerous for sheep.

Use of a block or licking stone not intended for sheep.

Leftover feed of another species distributed to the sheep so as not to lose it, mixtures made on the farm, poorly identified bags, delivery errors.

Grazing on plots that have received pig or poultry slurry rich in copper, or treated with copper products.

Water or drinkers in prolonged contact with copper parts.

Another, more discreet mechanism: a ration low in molybdenum and sulfur lets the sheep absorb much more copper, even without excess in the food. Certain regions and certain forages predispose to it.

Liver diseases, especially those linked to toxic plants or fluke, worsen the buildup.

Some breeds are known to be more sensitive than others.

Mixed farms where sheep and cattle, sheep and poultry, or sheep and pigs coexist: the risk of mixing feed is permanent.

Purchasing food without checking the species label on the bag.

Fattening lambs receiving lots of concentrate for weeks.

Animals at the trough, fed for a long time with the same ration: the accumulation is regular.

Ration low in molybdenum and sulfur.

Liver already weakened by fluke or toxic plants.

Periods of stress which trigger the crisis: transport, shearing, sorting, farrowing, high heat, batch change, eve of Eid.

Storage of food of different species in the same place, without clear separation.

Diagnosis and care

Diagnosis is the veterinarian's responsibility, based on clinical examination and laboratory tests. Care is decided case by case.

A yellow sheep with dark urine is an emergency: call the veterinarian the same day.

The veterinarian examines the color of the mucous membranes, collects urine and assesses the general condition. The combination of jaundice and port-colored urine in a sheep is very evocative.

Blood tests assess anemia and liver and kidney damage.

The dosage of copper in the blood helps, but it is sometimes misleading: it is above all the dosage of copper in the liver and kidney, carried out on a dead or slaughtered animal, which provides certainty. So never make a dead animal disappear without talking to the veterinarian.

The autopsy is very telling: yellow and crumbly liver, almost black kidneys, very clear blood.

Once the diagnosis is made, the most important work begins: identifying the source of the copper. The veterinarian examines the bags, labels, licks, water, ration and plot history. Without this investigation, the cases will continue for weeks.

Blood screening of animals from the same batch makes it possible to assess the extent of the overload in the herd.

Treatment

Once the crisis is triggered, the prognosis is very poor: most yellow animals die despite treatment. It is a disease that is won or lost before the signs.

The veterinarian can set up supportive care: infusions, treatment of liver and kidney damage, protection against stress, in cases where the animal still has a chance.

Treatments to block or eliminate copper exist and are given on prescription to the entire exposed flock, not just to the sick animal. Their nature, route and duration are strictly the responsibility of the veterinarian; used randomly, some of these products are themselves toxic.

The most urgent measure, and the one that really saves animals, is to immediately remove the source of copper: change the feed, remove the blocks, change the plot, and check each bag on the farm.

Absolutely avoid any stress on the exposed lot during the following weeks: no transport, no mowing, no rough sorting, no unnecessary handling. Each stress can trigger a new attack in a charged animal.

A veterinary check of the complete ration is essential before resuming normal driving.

Treatment depends on the cause and the animal's condition: it must be determined by a veterinarian. No self-medication.

Prevention

The rule is simple and absolute: never give sheep any food, concentrate, block or mineral supplement that does not explicitly bear the sheep label. No exceptions, even to help out one day.

Never feed leftover food from cows, calves, poultry or pigs to sheep, regardless of its apparent quality.

Store food of different species in separate and clearly identified places, and train everyone who distributes the food, including replacements and family.

Read the label on each new bag and check the copper content with the veterinarian or technician if in doubt.

Avoid grazing sheep on plots that have received pig or poultry slurry, or treated with copper products, without prior notice.

Talk to the veterinarian about the balance of the molybdenum and sulfur ration on farms with repeated cases.

If in doubt about a food already distributed, do not wait for the signs: have the situation assessed immediately, the window for action is before the crisis.

Reduce unnecessary stress during hot periods and before the holidays, when handling increases.

Possible complications

Death of the animal in the vast majority of declared crises.

Permanent destruction of the liver and kidneys in survivors, with animals never returning to their condition.

Serial mortality in the days and weeks following the first case, since the whole batch is loaded.

Heavy economic losses, primarily affecting the best-conformed animals.

Carcasses unfit for consumption in affected animals.

Discouragement and driving errors if the source is not identified: cases repeat themselves without explanation.

When to see a veterinarian

A sheep turns yellow: white of the eye, gums or skin. Call the vet the same day.

An animal urinates dark, dark red or port wine color: it is an emergency.

An animal suddenly stops eating and ruminating, becomes isolated and quickly weakens.

A sheep dies without prior signs after transport, shearing or sorting: have it examined rather than evacuating it.

You notice that your sheep have received food or a block intended for another species: call without delay, even if all the animals appear in good health.

Several animals from the same batch die within a few days of each other.

Prognosis

The prognosis for an animal in crisis is very poor: the destruction of red blood cells and liver damage are often irreversible by the time the breeder sees something.

The rare survivors have after-effects and do not regain their performance.

At the scale of the lot, everything depends on the speed with which the source is identified and eliminated: this is where animals are really saved.

A herd fed exclusively with sheep products almost never develops this disease: it is an entirely preventable poisoning.

Frequently asked questions

Can I feed my cows' feed to my sheep when I have some left?

No, never. It is the most common cause of copper mortality in sheep. Feeds for cattle, calves, poultry and pigs contain quantities of copper which are safe for these species but which sheep accumulate in their liver to the point of death. The mention of sheep on the bag is not a commercial detail: it is a question of survival.

My sheep have been eating cow feed for a few weeks but they are fine, should I be concerned?

Yes, and you have to call the vet even if everyone seems fine. The accumulation occurs silently and the crisis erupts weeks or months later, often after stress. It is precisely at this moment, before the signs, that taking charge of the lot can avoid losses.

Why do my most beautiful lambs die first?

Because they are the ones who ate the best, therefore those who accumulated the most copper. This is one of the most painful aspects of this poisoning: it primarily affects the best behaved animals.

Is a dead copper animal dangerous to my family?

Its carcass is not suitable for consumption and should not be eaten or given to dogs. It is not a contagious disease for humans, but for an animal whose organs are heavily loaded with copper and seriously damaged. Have him checked out by the vet, this will protect the rest of the flock.