Leishmanioses are a group of parasitic diseases that affect man and other mammals. They are caused by different species of trypanosomatids of the genus Leishmania Ross, 1903 and have tegumentary and/or visceral manifestations. The distribution of this re-emerging disease, which is found throughout the world (except in Antarctica), is influenced by various factors linked to both human activity and climatic change. The heteroecious life cycle of the Leishmania includes an invertebrate host (sandflies of the Phlebotomidae family). The dog is the main reservoir for many of the Leishmania species, simultaneously presenting both cutaneous and visceral clinical signs. The most frequent signs are skin abnormalities (dry exfoliative dermatitis, ulcers, periorbital alopecia and onychogryphosis), but ocular signs (keratoconjunctivitis and uveitis) and lymphadenomegaly are also common. Clinical diagnosis is difficult because of the great variety of symptoms and should, therefore, be confirmed by parasitological, serological and molecular methods. Several strategies are used to control the disease, including the treatment of infected animals. However, treatment failure is common and there is a risk that drug resistance will develop.