Home Animalia Animal health Animal diseases Leptospirosis

bacterial disease Dog, Cow Vaccine available Transmissible to humans

Leptospirosis

Leptospirosis is an infectious disease caused by bacteria of the genus Leptospira, affecting many animals including dogs, cattle, and pigs. It is a zoonosis, meaning it can be transmitted to humans. It mainly affects the kidneys and liver a...

What is it?

Leptospirosis is an infectious disease caused by bacteria of the genus Leptospira, affecting many animals including dogs, cattle, and pigs. It is a zoonosis, meaning it can be transmitted to humans. It mainly affects the kidneys and liver and can be severe if not managed promptly.

The disease is caused by spiral-shaped bacteria called leptospires, which exist in several strains. These bacteria survive well in moist environments such as stagnant water, mud, or waterlogged soil. They enter the body through mucous membranes or broken skin.

Animals living near stagnant water sources, wetlands, or in the presence of rodents are more exposed. Frequent contact with livestock or stray animals also increases the risk. Poor hygiene conditions on farms also favor the spread of the disease.

Commonly observed signs

These signs are neither exhaustive nor specific. Only a veterinarian can establish a diagnosis.

Signs may include fever, general fatigue, loss of appetite, vomiting, and increased thirst. In some animals, a yellowish discoloration of mucous membranes (jaundice) or urinary problems may be observed. In pregnant females, abortions can occur. Symptoms vary depending on the species and severity of infection.

When to consult without delay

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

Transmission

Transmission occurs mainly through contact with the urine of infected animals, either directly or via contaminated water or soil. Rodents are important carriers of the bacteria. Contamination can also occur during birthing or through contact with infected tissues, and humans can be infected in the same way.

Diagnosis and care

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

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If leptospirosis is suspected in an animal, it is important to consult a veterinarian promptly, as this disease can also pose a risk to humans. Only a professional can assess the situation and provide appropriate care. One should never attempt to treat the animal on their own.

Prevention

Vaccinating dogs and livestock against certain leptospira strains can help reduce risks, based on a veterinarian's recommendations. It is also advisable to limit animals' access to stagnant water and control rodent presence on farms. Good general hygiene and proper management of animal waste also help limit the spread.

References

WOAH — Organisation mondiale de la santé animale (ex-OIE)

OMS — Organisation mondiale de la santé

MSD Veterinary Manual

Content reviewed by the TunisieVet editorial team · Updated 08 August 2026

AT A GLANCE

AgentBacterium
SpeciesDog, Cow
VaccineAvailable
Transmissible to humansYes

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Affected species

This information is provided for educational purposes only and is not a substitute for a veterinary consultation. If you have any concerns about your animal's health, consult a veterinarian.

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