Leishmania infantum, flagellated protozoa (Phylum Sarcomastogiphora, Trypanosomatidae family)
Promastigotes extracellular flagellated forms can be found in sandflies or in culture, whereas dogs only harbour the intracellular, non-flagellar parasites known as amastigotes. They are oval in shape and measure 3-4 x 2 µm.
Phlebotomus ariasi is a sandfly which is active during the summer, mainly present in the West of the Rhone Valley (northern Spain, south-west of France)
Phlebotomus perniciosus is ubiquitous and is present all over the Mediterranean (two peaks: one in spring and one in autumn)
In Serbia and Croatia, the main vector is Phlebotomus perfiliewi.
In Greece it is principally Phlebotomus major.
Learn more about the vectors: Sandflies
Endemic in Italy (except Alpine areas), Sardinia, Sicily, Spain, Portugal, Corsica, Greece and the southernmost third of France. The infection prevalence is over 10% in some cities in southern France. Infection incidences vary with seasons: peak from spring to autumn but clinical expression occurs all year round, due to extremely variable incubation rates. The zoonotic parasite L. infantum infects Canids, either domestic or wild (foxes), but rodents may also be affected by certain strains, especially brown rats, mice and hamsters. The domestic reservoir of the parasite is the canine population. Cases of leishmaniosis have been described in cats and horses, but these are exceptional.
Leishmaniosis is a chronic disease.
General symptoms: Change in character (apathy, animal is less playful, dejected), amyotrophy, anorexia, weight loss, no fever in most cases but blood and biochemical changes: anaemia, leukopaenia, monocytosis and thrombocytopaenia are generally observed. Hyperproteinaemia (hyperglobulinaemia) is rapidly noted.
Cutaneo-mucous signs: depilation, dry dermatitis with squamosis, onychogryphosis, keratogenesis disorders, ulcers, and subcutaneous nodules (proliferation of macrophagic lines)
Signs related to the mononuclear phagocyte system: polyadenomegaly and splenomegaly.
Epidemiological and clinical considerations.
Laboratory
Monocytosis (4-10%), hyperproteinemia (55 g/l to 85 g/l or more), and hyperglobulinaemia, including gammaglobulinaemia (blocking of beta-gamma globulins).
Serology testing (indirect diagnosis) or looking for leishmania (direct diagnosis)
Differential
Skin diseases: scabies, pyoderma and autoimmune dermatoses.
Disease Type: cancerous development; erhlichiosis (apathy and epistaxis); systemic lupus erythematosus (clinical picture almost identical to that of leishmaniosis)
Before starting treatment, the owner should be motivated and the dog’s condition should be good enough.
- Meglumine antimoniate. The therapy needs to be implemented with the administration of liver protectors and diuretics.
- Allopurinol, oral intake, decrease the therapeutic failures. It is used as a cure for 30 days.
Certain molecules repel sand-flies, such as permethrin (spot-on) for 2 to 3 weeks and deltamethrin (pet collars) for several weeks or months (limited efficacy).
Cats can be the accidental reservoir of the parasite; ten cases of leishmaniosis have been described in Europe in the last ten years. The diagnosis and the treatment is the same as for dogs.