Leishmaniasis in dogs. Can symptoms be controlled?

Leishmaniasis in dogs is endemic to the Mediterranean region. In endemic areas, there is a very high level of contact with the parasite Leishmania infantum, but not all animals will go on to develop leishmaniasis.

In fact this is a peculiarity of leishmaniasis in dogs; a large percentage of animals that come into contact with the parasite do not go on to develop signs of the disease. This depends on the strength of the cellular immune response.

Despite being infected, these asymptomatic dogs do not develop the typical signs of the disease, such as:

• Non-suppurative granulomatous inflammation localised to areas of parasite multiplication (chronic hepatitis, dermatitis, chronic interstitial nephritis).
• Immune complex deposition in various organs (vasculitis, uveitis, glomerulonephritis and arthritis).

Dogs actually come into contact with the parasite when bitten by the mosquito Phlebotomus. Endemics depend on the mosquito’s life cycle. The mosquitoes hardly move from their central nucleus, resulting in hyperendemic foci within endemic regions. It is worth highlighting that the mosquito is the vector of the disease, but dogs are the main reservoir of Leishmania.

Dogs that live outdoors have the highest prevalence. The Phlebotomus mosquito feeds at dusk and dawn, which is when it can infect dogs.

Canine leishmaniasis has a long incubation period, from months to years.

When a patient does develop the disease, the appropriate treatment is very important.

As discussed in another post, leishmaniasis in dogs is usually treated with:

• Meglumine antimoniate 80 mg/kg/day for 45 days
• Allopurinol 10 mg/kg/12 hours for 90 days

In addition to drug therapy, we can also improve the clinical evolution by introducing a diet tailored to the animal’s disease. 

All of these interventions mean that while canine leishmaniasis remains a chronic, incurable disease, most dogs can continue to live a good life for many years.

Therefore, we can conclude that leishmaniasis in dogs is a controllable disease if the correct treatment and monitoring are established. The worst prognosis is seen in dogs that develop kidney failure at the outset. Besides treating Leishmania as the disease evolves, the possibility of other parasitic diseases such as babesiosis or ehrlichiosis must also be taken into account.