Avoid letting your dog contract leptospirosis

Leptospira is a bacterium that can infect dogs, humans and other animals. The bacterium thrives best in warm and humid climates but is sometimes found in dogs in Sweden as well. Usually an infection causes no or mild symptoms but in some cases the bacteria can lead to serious illness and is therefore good for you as a pet owner to know about.

What is leptospirosis?

Leptospira is a bacterium that is found all over the world, including in Sweden. However, it thrives best in temperatures between 15-25 degrees and is therefore more common abroad. Dogs are often infected indirectly through their environment, including rodents. Infected animals excrete the bacterium through urine and the transmission of the bacterium occurs via, for example, stagnant, warm water. Direct infection between animals can also occur through bites or the dog eating an infected animal, such as a rat or mouse. The disease is a so-called zoonosis, which means that it can be transmitted to humans.

What symptoms does the dog get?

What symptoms the dog gets and how severe they are depends on the amount of bacteria the dog has ingested and the dog's immune system. Usually the bacteria cause only mild symptoms or no symptoms at all. However, puppies and young dogs that are infected can develop severe disease with liver and kidney damage. The dog may then show symptoms such as fever, vomiting, blood in the urine or faeces and unwillingness to move.


Leptospirosis is treated with antibiotics and therapy to relieve symptoms. Sometimes the dog may need to be admitted to a veterinary hospital for intensive care if the disease has progressed.


In most parts of Sweden, dogs do not need to be vaccinated regularly against leptospirosis. However, vaccination may be necessary if several dogs in the same area are affected by the disease. Check with your local vet if this is something that is recommended for dogs where you live. Vaccination does not provide complete protection and even vaccinated dogs can become infected and spread the bacteria further. However, the vaccine appears to protect against more serious disease.

If you are travelling abroad with your dog, it may be a good idea to vaccinate your dog against leptospirosis before you leave. Remember that a basic vaccination against leptospirosis involves two injections at one-month intervals, so make sure you are out well in advance of your trip. The onus is on you as a pet owner to find out what vaccinations are recommended in the country you are travelling to.

Prevent infection

  • Ask your vet about recommended vaccinations for your dog

  • If you are travelling abroad:
    - Check with the country you are going to what vaccinations are recommended
    - Leptospirosis is most contagious in areas where dogs are crowded, such as dog parks, playgrounds or urban areas, so try to avoid these environments as much as possible
    - Try to avoid your dog drinking from stagnant water

Read more about Leptospirosis in dogs on the SVA (Swedish Veterinary Medical Institute) website.
If you want more information about Leptospirosis in humans, you can read more on the Public Health Agency's website.

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