Dogs Health Cards N° 17. Leptospirosis



Leptospirosis is an infectious disease caused by the presence of bacteria called leptospires which can infect humans, dogs and many animal species (cat, rat, mouse, gerbil, hamster, ferret ...). This pathology is much more common in dogs than in cats.

The transmission of leptospirosis

The dog is contaminated directly by contact with wild rodents or indirectly through the urine present in the outside environment (leptospires resist well in wet and shady areas such as rivers, ponds, ponds, earth, mud ...)

Leptospires enter a man's body by contact with one of his mucous membranes (mouth, eye, respiratory tract), or a wound he has made, with blood or secretions from a person Infected animal for a few days. After about 8 days, it is the urine of the diseased animals which becomes contaminating, including by their presence in the external environment. The man can therefore contract the disease by contact with the urine of a dog or a rodent of company ill but even more by contact with the urines of wild rodents present in the freshwater areas ..)

Professionals in frequent contact with wild or domestic animals and people enjoying aquatic recreation are therefore particularly exposed to the disease.

The manifestations of the disease

- The dog may develop an acute form of leptospirosis. He died in a few hours.

An acute form of the disease is also described: the dog has a high fever associated with liver and kidney problems. Hemorrhagic gastroenteritis may also occur.
In this form of leptospirosis, the prognosis depends very much on the rapidity of implementation of the treatment.

In rare cases, chronic liver or kidney failure may result from leptospiral infection.

Finally, the dog can excrete the bacteria in the absence of any symptoms.

- Small rodents such as hamster or guinea pig are susceptible to the disease until the age of 6 months. Then they become asymptomatic carriers, that is, their urine contains the leptospires without them being sick.
In the same way, infected rats and mice reject the bacteria in their urine without being sick.

- In man, leptospires multiply in the blood and then distribute throughout the body with a preference for certain tissues like the liver or the kidneys.

Very different clinical pictures follow the infection with leptospires:

  • Acute leptospirosis can cause sepsis (generalized infection associated with the multiplication of bacteria in the blood)
  • Most often, leptospirosis causes ictero-hemorrhagic syndrome: the patient suffers from haemorrhagic disorders associated with liver damage causing the appearance of a "jaundice"
  • More rarely, meningitis, lung disorders or even chronic renal insufficiency are described.

The diagnosis of leptospirosis and its treatment

The diagnosis of leptospirosis in animals (especially in dogs) calls for:

- A search for the bacterium in the blood of the animal during the first 5 days of infection

- After 10 to 15 days, the leptospires can be highlighted in the urine of the dog

- Finally, antibodies directed against leptospires can be looked for about 10 days after the onset of the first symptoms.

The treatment of leptospirosis involves antibiotics. The earlier this treatment begins, the greater the chances of survival of the animal.

The means of combating leptospirosis

The protection of the dog requires regular vaccination against the disease: The vaccine will avoid the clinical expression of leptospira infection and in particular the appearance of fatal forms of the disease.

As far as the human is concerned, the vaccination of its pets is not sufficient to ensure total protection:

- An animal, even when vaccinated, may remain receptive to wild strains and become a leptospiral shedder.

Certain precautions must therefore be observed:

Wear gloves to handle an animal suffering from gastroenteritis, especially to clean its soils, and think about disinfecting the site with bleach.
Buy rodents in health-controlled production centers, avoid contamination by not letting them roam the natural environment (lawns, etc.) and observe strict hygienic measures to handle their urine.
As we have seen above, man can contract the disease in contact with water contaminated by the urine of excreting wild animals (wild animals are the main reservoir of leptospires). It will therefore be necessary to avoid bathing or staying in ponds, ponds or contaminated rivers.