The Canine Leishmaniasis Working Group (CLWG) has been established with the aim of obtaining a rational and homogeneous approach to the canine patient with clinical leishmaniasis. Canine leishmaniasis is a systemic chronic disease caused by Leishmania infantum, transmitted by vectors (phlebotomine), which is endemic in the Mediterranean basin. The dog represents the main reservoir of the infection. The parasite is inducing a strong immunity response, which is the cause of organ injuries found in the diseased dogs.