Leptospirosis is a disease caused by the Leptospira interrogans bacterium, which can survive for several years in warm, humid and shady environments.  

It is a zoonotic disease, which means that animals can transmit it to humans.

At-risk animals

Leptospirosis affects mainly dogs, horses, cattle and pigs. It can also affect cats, goats, sheep, rabbits and rodents. 

Wild animals can also be infected, including mice, rats, racoons and skunks. 

Signs of the disease

In dogs, leptospirosis can lead to acute renal impairment and hemorrhagic gastroenteritis.

In horses, signs include a fever, anorexia, jaundice and uveitis of the eye. It can also lead to abortions.

In cattle and adult pigs, leptospirosis appears in the form of a fever, anorexia, infertility and udder inflammation. It also causes a stark drop in lactation and leads to abortions or stillbirths. Young cattle and pigs can have a fever, blood in their urine, jaundice and diarrhea.

Protection and prevention

Wild animals are primarily responsible for spreading the bacteria in the environment.

Several measures can help prevent the disease in animals and its transmission to humans.


Dogs, cattle and pigs can be vaccinated against leptospirosis. Vaccination does not fully prevent infection, but it reduces its likelihood and duration. Vaccination is not yet available for horses.

At home

To avoid transmission, follow the appropriate personal hygiene (in French only) measures. Wash your hands after touching an animal.

Avoid drinking, eating or smoking while grooming or caring for animals, and while cleaning out their cage. Wear gloves and protective gear when you are caring for animals.

Do now let dogs drink from or walk on pools of water that may have been contaminated by wild animals, for example in public parks. Do not let your dog near wild animals. 

Check for vermin and fence vegetable gardens to keep animals out. 

Do not swim in ponds that may be contaminated. Avoid contact with the urine of animals that are infected or that you suspect to be infected, whether they are sick or recovering.

Strictly follow the vaccination protocol recommended by your veterinarian.

On a farm

You can take certain precautions to reduce the risk of leptospirosis transmission.

If possible, drain marshlands.

Ensure that your buildings are rodent-proof and keep vermin away from your animal feed.

In pet shops and veterinary clinics

Following the appropriate hygiene measures can help prevent contamination. Wash your hands after handling animals and at the end of each work day. Change your work clothes every day.

Avoid eating, drinking, smoking or storing food in animal facilities.

Wear latex gloves and a long-sleeve lab coat when in contact with an animal that may be infected or that has had leptospirosis in the past few months. Bacteria may be excreted in urine for months or even years after clinical signs have disappeared.

Avoid contact with the urine of animals that are infected or that you suspect to be infected, whether they are sick or recovering. In clinics, it is recommended to install a urinary catheter connected to a waterproof bag in order to avoid contaminating the environment. 

If there is urine on the floor, carefully cover the puddle with paper towels and apply bleach from the outside toward the centre. Let it sit for at least 30 minutes before cleaning. Soak the mop you used to clean the area in disinfectant permanently. You must wear gloves the whole time.

In humans

Infected animals that do not show any symptoms can still transmit the disease.

A person can contract leptospirosis through the skin and through the mucous membrane of the nose, mouth or eyes. For example, you can contract the disease if you swim in a contaminated watercourse.

The disease can propagate through direct or indirect contact with the urine of infected animals or with placental or fetal tissue from abortions.

The parasite is also transmitted in areas contaminated with animal urine, such as a watercourse or grassland.

Symptoms appear from 1 to 2 weeks after contamination. Infected people generally have a fever, chills, headaches, muscular pain and fatigue. In 10% to 15% of cases, leptospirosis leads to jaundice caused by liver, kidney and blood-related issues.

Recovery takes from several days to several months.

Last update: January 8, 2024


Was the information on this page useful to you?
General notice

You have questions or require additional information?

Please contact Services Québec