What is leptospirosis?
Leptospirosis is a serious infectious disease caused by bacteria called Leptospira interrogans or leptospira.
The disease manifests itself in various forms and with various symptoms, but the most serious forms lead to kidney and liver damage, which can be fatal for the dog.
How can a dog get leptospirosis?
Leptospira interrogans, the agent in question
The agent involved in the disease is a bacterium that belongs to the order of spirochetes and is called Leptospira interrogans, or more commonly leptospira.It exists under several serovars among L. icterohæemorrhagiæ, L. canicola or even L. grippotyphosa.
The reservoir species of this bacterium is mainly the rat but also other rodents such as the nutria, and other small mammals such as the hedgehog. These small animals are he althy carriers of the bacteria (they have the bacteria in their body but it does not make them sick) and then excrete it in their urine, which can contaminate stagnant fresh water and soil.
Bacteria can survive for several months in the outdoor environment and when the conditions are favorable for their survival, in a warm and humid environment. This is one of the reasons why the incidence of the disease is higher in late summer and autumn
Contamination by contact with infected urine
Leptospires enter the dog's body through mucous membranes and skin wounds.Thus, a dog is most often contaminated by drinking or bathing in fresh water contaminated with urine from infected animals (urine from rodents, small mammals but also from another infected dog).
More rarely, the disease is transmitted by the bite of an animal carrying the bacteria or by ingesting infected meat.
Attention, disease transmissible to humans
Leptospirosis is a zoonosis. In other words, it is a disease that can be transmitted from animals to humans. Like dogs, humans become infected when one of their mucous membranes (nose, mouth, eye) or skin wounds comes into contact with the secretions of an infected animal.
What are the symptoms of leptospirosis in dogs?
The incubation period for the disease is usually 4 to 12 days, although some dogs may show symptoms much faster.
The disease can manifest itself in different forms: hyperacute, subacute or chronic. The peracute form leads to rapid death of the animal, generally within 48 hours of the appearance of the first signs.
The first symptoms of the disease are generally non-specific. They can include fever, anorexia and a certain depression of the dog.
Then appear other symptoms among:
- Ichterus (or jaundice) and diarrhea containing blood, signs of liver damage,
- polyuro-polydipsia (the dog drinks and urinates a lot before stopping urinating), vomiting, diarrhea, weight loss, blood clotting disorders and abdominal pain likely to reflect acute kidney failure .
You can also experience other symptoms such as hemorrhagic gastroenteritis, uveitis, meningitis or diffuse muscle pain.
How is leptospirosis diagnosed in dogs?
When the veterinarian suspects leptospirosis in a dog, he will carry out a battery of tests including blood tests, urine tests and chest and abdominal X-rays.
But, the diagnosis of certainty can only be obtained from:
- a serology that measures the level of antibodies directed against the bacteria responsible for the disease in the dog's blood. On the other hand, serology is done too early at the onset of the disease, it can be negative and delay the final diagnosis.
- and/or a search for the bacteria by the PCR method from blood, urine, aqueous humor or cerebrospinal fluid. This technique, which is very sensitive and specific, is however only indicated if the dog has not yet received antibiotics.
What is the treatment for leptospirosis?
The specific treatment of leptospirosis involves the administration of antibiotics to the dog, most often intravenously.
In the vast majority of cases, the treatment requires hospitalization for several days during which the dog will be placed in intensive care and put on a drip in an attempt to correct the disorders caused by acute renal failure.
The earlier the treatment is put in place, the better the chances of recovery for the dog, although more or less serious renal or hepatic sequelae may then persist. Sadly, nearly one in two dogs with leptospirosis dies despite intensive care.
Vaccination, an effective means of prevention?
There is a leptospirosis vaccine that is routinely included in all dog vaccination programs. Although it reduces the risk of contracting leptospirosis or developing severe forms of the disease, this vaccine is not 100% effective.
As its duration of action is relatively short (about 10 months), it is advisable to carry out a booster every 6 months in dogs particularly exposed to the disease, such as hunting dogs for example.
Prevention against this disease also means not letting your dog drink in stagnant puddles of fresh water or letting it bathe in bathing water whose sanitary quality is not controlled.