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bacterial disease Sheep, Goat Vaccine available Transmissible to humans

Q fever

Q fever is a disease caused by a very resistant bacteria, Coxiella burnetii, which affects sheep, goats and cattle. In small ruminants, it most often goes unnoticed: the animals do not appear sick. It is revealed by abortions, often at the...

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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?

Q fever is a disease caused by a very resistant bacteria, Coxiella burnetii, which affects sheep, goats and cattle.

In small ruminants, it most often goes unnoticed: the animals do not appear sick. It is revealed by abortions, often at the end of gestation, and by lambs or kids who are stillborn or too weak.

At the time of birth or abortion, the infected female sheds massive amounts of bacteria into the placenta, fluids and secretions. These bacteria resist drought and are found in dust, where they survive for months.

Key point

Major zoonosis. Abortions and births are the most dangerous times for those present. Gloves, mask, no handling with bare hands, and strict avoidance of pregnant women and vulnerable people.

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:

Abortion Vulvar discharge Infertility Retained placenta Fever Fall in milk production Stunted growth

In sheep and goats, the disease is most often silent: no visible signs, no change in condition or appetite.

Abortions, especially in the last third of gestation, sometimes serially in the herd.

Premature births, stillborn lambs or kids, or born alive but very weak and do not survive.

Retention of the placenta and prolonged vulvar discharge after parturition.

Reduced fertility and repeated returns to heat in affected herds.

Females generally abort only once, then carry their subsequent pregnancies to term, although they may continue to shed the bacteria during births.

Contrary to what its name suggests, fever is not a characteristic sign in animals; the name comes from the disease described in humans.

When to consult without delay

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

Causes and risk factors

The disease is caused by the bacteria Coxiella burnetii, which particularly multiplies in the placenta of pregnant females.

It has a form of resistance which allows it to survive for a very long time in the external environment: in dust, straw, manure, wool, it remains infectious for months.

An infection during gestation leads to damage to the placenta and therefore to abortion or the birth of a non-viable young person.

Many wild animals and ticks participate in the circulation of the bacteria in the environment.

Breeding of small ruminants with grouped births in the same premises.

Dusty, poorly ventilated buildings with accumulated litter.

Abortions handled carelessly: abortions and placentas left on the ground or thrown away without being disposed of.

Manure stored near homes or spread without precaution in dry and windy weather.

Purchases of animals without knowledge of health status.

Mixing of herds, transhumance, gatherings and markets.

Presence of ticks and contact with wildlife.

Transmission

Between animals, mainly by inhalation of contaminated dust: this is the dominant route.

By birthing and abortion products: placenta, liquids, abortions, soiled litter, extremely rich in bacteria.

Through milk, urine and droppings of infected animals, in smaller quantities but over long periods.

Dried bacteria travel with the wind, dust from manure and air movements from buildings: contamination at a distance from the farm is possible.

Ticks are involved in the wild cycle of the bacteria.

Manure transport and spreading are recognized sources of dispersion.

Diagnosis and care

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

Before any abortion, and even more so before several abortions close together, you must call the veterinarian: this is a health obligation in many countries and a necessity for people's health.

The veterinarian takes samples from the placenta, the runt and the mother's blood, sent to the laboratory.

At the same time, he is researching other causes of abortion in small ruminants, several of which are also transmissible to humans: this is why we are never satisfied with a hypothesis.

Analyzes of tank milk or environmental samples can complete the herd-wide assessment.

Always handle samples with gloves, and keep aborts and placentas safe, in a closed container, while waiting for the veterinarian.

Treatment

There is no treatment to eliminate the bacteria from the herd.

Antibiotics from the tetracycline family are sometimes used to limit abortions during a risky period, on the veterinarian's decision. Their effect is partial: they reduce losses without eliminating the excretion of bacteria, and therefore without eliminating the risk for people.

Control is therefore primarily based on breeding management, farrowing management and vaccination, not on medications.

Withdrawal periods for milk and meat must be respected after any treatment.

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

Prevention

Isolate females that abort, and manage births in a dedicated, easy-to-clean room.

Immediately pick up placentas, abortions and soiled bedding with gloves and a mask, place them in a closed container and dispose of them according to your veterinarian's instructions. Never leave them on the ground, never give them to dogs.

Avoid dry sweeping and handling dusty litter in buildings: humidifying before cleaning greatly reduces the suspension of bacteria.

Compost and store manure away from homes, avoid spreading it in dry and windy weather.

Control ticks on animals, according to the veterinarian's advice.

Limit introductions and know the status of animals purchased.

Do not consume raw milk from herd animals.

Inform anyone working in livestock farming of the risk and precautions, particularly pregnant women and vulnerable people.

Vaccination

A vaccine intended for ruminants exists and constitutes the most effective tool for reducing abortions and especially the quantity of bacteria released into the environment, and therefore the risk for people.

It is all the more effective as it is administered to females not yet infected, before mating: vaccination is therefore reasoned in advance, with the veterinarian, in the herd's reproduction calendar.

Vaccination must be continued for several consecutive years to produce a lasting effect on an affected herd.

Its availability varies depending on the country: your veterinarian will tell you what is possible locally.

Vaccination never exempts from hygiene precautions at the time of giving birth.

Possible complications

Serial abortions and significant losses of young over a season.

Retained placenta and uterine infections after giving birth.

Long-term decline in fertility and lengthening of intervals between births.

Contamination of the breeding environment for many months, with a persistent risk for people.

Human cases among the breeder, his family or the neighborhood of the farm.

When to see a veterinarian

A female aborts: call the veterinarian, do not throw away the abortion and handle it with gloves.

Several abortions occur in a short time in the herd: it is a health alert, never a coincidence.

Lambs or kids are born dead or too weak to stand up and nurse.

Retained placenta and prolonged discharge affect many females.

The fertility of the herd is declining without explanation.

A person on the farm has a prolonged fever, intense headaches or unusual fatigue: they must consult a doctor, reporting their contact with ruminants.

Transmission to humans

Q fever is a disease transmissible to humans, and it is in humans that it is most poorly known as a benign illness.

Contamination occurs mainly through the air: by inhaling dust containing the bacteria, in a building, by cleaning litter, by handling manure, or simply by living near a farm affected during births. It is not necessary to touch an animal to be contaminated.

Birthing and abortion products are by far the most dangerous source: placenta, fluids, abortions. Never handle them with bare hands. Wear gloves and a mask, moisten before curing, and dispose of this waste in a closed container.

Raw milk and raw milk cheeses from infected animals constitute a second route of contamination: do not consume raw milk from your herd and do not give it to your children.

In humans, the infection often goes unnoticed. When it manifests itself, it is by high and prolonged fever, violent headaches, muscle pain, severe fatigue, sometimes damage to the lungs or liver. A chronic form, rarer and more serious, can affect the heart months or years later.

Certain people are particularly exposed to serious forms and must be kept away from births, abortions and dusty premises: pregnant women, in whom infection can lead to abortion or premature birth; people with heart disease or a heart valve; immunocompromised people; the elderly.

A pregnant woman should never intervene in a lambing, nor handle an abortion or placenta, nor clean a birthing area.

Anyone on the farm who presents with an unexplained prolonged fever must consult a doctor and tell them that they work with ruminants: this information changes the diagnosis and treatment.

Prognosis

For the animal, the vital prognosis is rarely at stake: females who abort recover and most often carry their next pregnancies to term.

The problem lies elsewhere: losses of young over a season can be heavy, and the bacteria settles in the breeding environment for a long time.

Control requires consistency: rigorous management of births, vaccination over several years, precautions at each lambing.

The risk to people remains the most important point to consider, and it does not disappear because animals appear healthy.

Frequently asked questions

My sheep look in great shape: could there be a risk for me?

Yes. This is the particularity of this disease: infected animals appear normal and yet shed a lot of bacteria at the time of giving birth. Human contamination occurs by breathing dust, without it being necessary to touch a sick animal.

My wife is pregnant and lives on the farm: what should I do?

She must not intervene on lambings, nor handle aborts, placentas or soiled litter, nor clean the birthing premises, and she must avoid entering the buildings during the birthing period. She should not consume raw milk. Talk to his doctor, reporting the breeding activity.

What to do with an abortion?

Wear gloves, never touch it with bare hands, place it with the placenta in a closed bag or container, keep it away for the vet, and never give it to dogs. Then clean the area, without dry sweeping, and wash your hands thoroughly.

Can we eliminate bacteria from livestock?

Not quickly. It survives for months in dust and manure. We act over time: vaccination for several years in a row, strict management of births and abortions, humidification before cleaning, rational storage and spreading of manure.