Leishmaniasis in the increase : how to protect our pets?

Leishmaniasis is a serious chronic parasitic disease. When it occurs, it can be fatal if left untreated. Dogs are the main reservoir of the disease. In France, an estimated 40,000 new clinical cases of canine leishmaniasis occur every year.

A vector-borne infectious disease

Canine leishmaniasis is an infectious disease caused by a protozoan parasite called Leishmania infantum. Dogs are the main species affected, but cats and other mammals may also be affected to a lesser extent. This disease is a zoonosis, meaning that it can be transmitted from animals to humans and vice versa. To date, however, it is mainly immunocompromised people who are more prone to this disease.

Leishmaniasis is a vector-borne disease, meaning that the development cycle of the leishmania parasite requires it to pass through an intermediate host: the sandfly. A dog contracts leishmaniasis from a sandfly bite. Exposure is highest in areas where these insects live, i.e. in France, the southern third of the country and the countries of the Mediterranean basin (Spain, Italy, Greece, North Africa, etc.).

Clinical signs: how do you recognise the disease?

A dog carrying leishmaniasis does not necessarily develop the disease. In fact, 10% of dogs are healthy carriers, compared with 90% who develop clinical signs.

Since leishmaniasis targets macrophages, any organ or tissue containing these cells can be affected. The resulting clinical signs are therefore highly varied. The main lesions may be localised to the skin (loss of hair, ulcers, rapid growth of claws, squamosis, thickening and discolouration of the skin, appearance of nodules) or to the viscera (visceral lesions), in which case we speak of general leishmaniasis (muscle wasting, loss of weight and appetite, behavioural changes, hyperthermia). The lesions appear after a very long incubation period, which varies greatly in the case of leishmaniasis, lasting between 3 months and 1 year.

Although there are a number of measures to combat leishmaniasis, it is important to remember that it is a chronic disease that often leads to the death of the animal because its immune system is unable to eradicate the leishmania.

Reducing the risk of transmission: how can we protect our pets?

Leishmaniasis is therefore a serious disease, and reducing the risk of transmission is essential. It is important to make dog owners aware of this disease and to inform them of the means of prevention:

  • Use an antiparasitic repellent and/or insect repellent with a marketing authorisation against sandflies throughout their period of activity, even for a short stay in an endemic zone (zone with indigenous cases on the map):
  • Avoid going out at dusk or dawn
  • Vaccinating uninfected dogs

Marie SEGOVIA | Veterinarian and Pharmaceutical Manager