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bacterial disease Sheep, Goat Vaccine available Transmissible to humans

Ovine leptospirosis

Leptospirosis is caused by thread-shaped bacteria, leptospires, which live in the kidneys of infected animals and are excreted in their urine. These bacteria survive for a long time in fresh water, mud and moist soil, as long as it is not t...

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

What is it?

Leptospirosis is caused by thread-shaped bacteria, leptospires, which live in the kidneys of infected animals and are excreted in their urine.

These bacteria survive for a long time in fresh water, mud and moist soil, as long as it is not too cold or too dry. Ponds, ditches, soiled water troughs, flood zones and trampled puddles are their favorite environments.

In sheep, the disease takes two faces. An acute form, especially in lambs, with fever, jaundice and red urine, which can kill within a few days. And a discreet form in adults, which essentially results in abortions, weak lambs and a drop in production, without any animal appearing really sick.

Key point

Leptospirosis is transmitted to humans through animal urine and contaminated water, and it can take serious forms. Wear gloves when giving birth and handling runts, cover your wounds, and if you have a fever with severe headache and pain in the calves after working in contact with the herd, consult a doctor, specifying your profession.

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:

Fever Abortion Jaundice Dark urine Blood in urine Pale mucous membranes Fall in milk production Reduction Loss of appetite Lying animal that does not get up

In lambs and young people, acute form: high fever, profound depression, refusal to suckle or eat.

Very dark, red or brown urine: this sign, associated with jaundice, is the most suggestive of the disease in a young sheep.

Marked jaundice of the whites of the eye, gums and skin.

Pale mucous membranes from destruction of red blood cells, rapid breathing, weakness.

Animals that lie down and never get up again, possible death within a few days.

In adults, discreet and often silent form: it is the herd that speaks rather than the individual.

Abortions, generally at the end of gestation, stillborn or very weak born lambs which die quickly.

Fall in milk production, milk with an abnormal appearance, soft and flabby udder without being painful.

Infertility and return to heat.

Kidney damage over time in certain animals, which slowly lose weight.

Many infected animals show nothing at all while shedding bacteria in their urine for months.

When to consult without delay

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

Causes and risk factors

Infection by bacteria from the leptospira group, several types of which circulate depending on the regions and animal species present.

Infected animals harbor the bacteria in their kidneys and shed it in their urine, sometimes for months, without becoming ill.

Urine contaminates water, mud, pastures and food.

Bacteria enter through the mucous membranes of the mouth, nose and eyes, and through skin damaged or simply softened by prolonged contact with water.

Rodents constitute the main reservoir and contaminate silos, attics, troughs and water troughs.

Other farm animals, including cattle, dogs and pigs, can keep traffic moving.

Leptospires die quickly in a dry, acidic or salty environment: this is a useful point, because it explains why drying and cleaning are so effective.

Wet pastures: ponds, ditches, river banks, flood-prone areas, irrigated plots.

Drinking from natural water points rather than from a trough.

Periods of heavy rain, floods and high waters, and hot and humid seasons.

Significant presence of rodents around buildings, silos and food stocks.

Cohabitation with cattle, pigs or carrier dogs.

Introduction of animals without quarantine.

Damp buildings, soggy litter, muddy watering areas.

High density of animals and poorly cleaned milking equipment.

Transmission

Contamination occurs through contact with the urine of an infected animal, directly or, more often, through the water and mud it has contaminated.

Natural watering points, ponds, ditches, flood zones and trampled puddles are the most common places of transmission.

Food and fodder soiled by rodent urine also contaminate.

Transmission can occur from mother to lamb during gestation, which explains abortions and weak lambs.

Newly introduced animals can bring the bacteria onto a farm unharmed, without showing the slightest sign.

For humans, contamination occurs through contact of damaged skin or mucous membranes with contaminated urine, water or mud, as well as during milking, assistance with giving birth and slaughter.

The disease is not transmitted from one person to another.

Diagnosis and care

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

A yellow lamb that urinates red must be seen quickly: several serious diseases give this picture and the veterinarian must distinguish them.

The veterinarian examines the animal, collects urine and assesses anemia and liver and kidney damage through blood tests.

The definitive diagnosis requires the laboratory: search for the bacteria or its genetic material in urine and organs, and search for antibodies in the blood. Analyzes are preferably carried out on several animals in the herd, including apparently healthy animals, because it is the collective image that counts.

In the event of an abortion, the veterinarian removes the placenta and the runt, handling with protections.

He rules out other causes of abortions in sheep, which are numerous and most of which are transmissible to humans: brucellosis, Q fever, chlamydiosis, toxoplasmosis. This distinction completely changes the precautions to take.

In a yellow lamb, it also rules out copper intoxication, which gives a very similar picture and requires completely different behavior on a flock scale.

The veterinarian finally inspects water points, wet areas and the presence of rodents: this is where the lasting solution lies.

Treatment

Antibiotic treatment exists and is effective, particularly if it is started early in the acute form. The choice of molecule, route and duration are up to the veterinarian.

The treatment has two distinct objectives: to treat sick animals, and to reduce the elimination of bacteria by the carrier animals, which protects the rest of the herd and people.

Supportive care accompanies: infusions, protection of the liver and kidneys, rest, clean water.

The most affected animals, very anemic and yellow, need intensive care and have a guarded prognosis.

Treatment of the entire herd may be decided by the veterinarian during an episode, in particular to interrupt carrying.

Waiting times for meat and milk must be strictly respected and will be specified to you by the veterinarian.

No antibiotic should be used without a prescription or diagnosis: in this disease, poorly conducted treatment leaves carriers who continue to contaminate water and people.

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

Prevention

Drain and fence off wet areas accessible to the herd: ponds, ditches, shallows, permanent puddles. This is the most effective measure, as for liver fluke.

Drink from the trough, with clean water, and clean the troughs regularly rather than letting the animals drink from natural water points.

Repair leaks, drain areas around watering troughs and avoid areas of trampled mud.

Actively control rodents around buildings, silos and feed stocks, and store feed under cover.

Quarantine any introduced animal and talk to the veterinarian.

Avoid mixing sheep with cattle or pigs on damp plots without notice.

Maintain dry litter and well-drained buildings.

Wear gloves during any intervention during parturition, when handling runts and during milking, and cover any wounds on the hands and arms.

Discuss vaccination with the veterinarian on farms with repeated problems.

Vaccination

Vaccines against leptospirosis exist in farm animals, but their availability and their interest in sheep vary greatly depending on the country and the types of leptospires circulating locally.

A vaccine only protects against the types it contains: this is why the choice must be based on the results of analyzes carried out on the farm or in the region, and not on a general decision.

Vaccination never replaces the sanitation of water points and the fight against rodents, which remain the basic measures.

The question arises especially in farms which encounter repeated episodes of abortions or lamb deaths despite correct hygiene measures.

Talk to your veterinarian, who knows the local situation and the products actually available.

Possible complications

Death of lambs affected by the acute form, despite treatment in the most advanced cases.

Long-lasting renal failure in survivors, with animals never returning to their condition.

Repeated abortions and infertility, with a compromised breeding season.

Lambs born weak that die within the first few days.

Prolonged fall in milk production.

Prolonged silent carrying, maintaining contamination of pastures, herds and people.

Contamination of people on the farm, which is the most serious complication.

When to see a veterinarian

A lamb turns yellow and urinates red or brown: call the veterinarian the same day.

Ewes abort, especially at the end of gestation: do not handle the aborts with bare hands and have them analyzed.

Lambs are born weak and die within the first few days.

Milk production drops suddenly in the herd without visible mastitis.

Animals are slaughtered, feverish or anemic after a period of heavy rain or flooding.

You have fever, headache, intense muscle pain or red eyes after working in contact with animals or water: consult a doctor and report your activity to him.

Transmission to humans

Leptospirosis is a well-identified zoonosis, considered an occupational disease of the livestock industry in many countries.

Human contamination occurs through contact of damaged skin or mucous membranes with the urine of infected animals, or with the water and mud it has contaminated. Helping a sheep to give birth, picking up a runt, milking, cleaning a damp sheepfold, working barefoot in a puddle or ditch are risky situations.

In humans, the disease begins like a severe flu: sudden fever, intense headache, marked muscle pain particularly in the calves, red eyes. Many cases recover, but some develop into serious forms, with jaundice, kidney damage, bleeding and lung damage, which can be fatal.

There is an effective antibiotic treatment, especially if it is started early: this is why you must consult quickly and tell the doctor that you are working with animals. This precision often changes the diagnosis.

Concrete precautions: gloves for any intervention during birth and for handling runts, boots and work clothes, cover any wound before working, wash your hands, do not drink untreated water or raw milk, and avoid working barefoot in muddy areas.

Particularly protect children and prevent them from playing in puddles and areas trampled by animals.

Prognosis

The acute form of lambs, with jaundice and red urine, has a guarded prognosis: some die despite rapid treatment, and survivors often have kidney damage.

Adults with the mild form usually recover, but may remain carriers and continue to shed bacteria for months.

The consequences on the reproduction of a season are irrecoverable.

At the herd level, the prognosis depends above all on the control of wet areas and rodents: without this, the disease returns despite treatment, exactly as with liver fluke.

Frequently asked questions

My lamb has jaundice and red urine, is it leptospirosis?

This is one of the possible causes, but not the only one: copper poisoning gives exactly the same picture in sheep and requires completely different behavior for the whole flock. Only the veterinarian can make the difference, and the stakes are real since the measures to be taken are not the same.

How did my sheep get this?

Almost always by water: a pond, a ditch, a muddy puddle or a water trough soiled with the urine of infected animals or rodents. The bacteria survives for a long time in fresh water and mud, and much worse in a dry environment, which explains the effectiveness of drainage.

Am I in danger caring for my sheep?

The risk exists and it is recognized as professional in many countries. It focuses on farrowing, handling runts, milking and working in muddy areas. Gloves, boots and covering wounds greatly reduce this risk.

Is there a vaccine for my herd?

Vaccines exist, but their availability in sheep and their suitability depends on the types of leptospires circulating in your area. They only protect against what they contain. This is a discussion to have with your veterinarian, based on analyses, and never a substitute for sanitation of water points.