Canine Leishmaniasis in Brazil: A Review of Infection Prevalence and Histopathological Characterization of the Skin in Dogs Naturally Infected with Leishmania infantum Submitted to Treatment with Marbofloxacin.
Zoonotic diseases; canine reservoir; vector-borne diseases; histopathological analysis; One Health
Leishmaniases are chronic anthropozoonotic diseases caused by protozoa of the genus Leishmania, endemic in more than 98 countries and classified by the WHO as neglected diseases, with over 1 billion people exposed to the risk of infection. The visceral form is caused by Leishmania infantum and, in Brazil, is mainly transmitted by Lutzomyia longipalpis and Lutzomyia cruzi. Dogs play a significant role in maintaining transmission, as they may present from asymptomatic infection to severe clinical manifestations. Considering its relevance within the One Health framework, the studies aimed to review the prevalence of canine visceral leishmaniasis (CVL) in Brazil and to evaluate histopathological skin alterations in treated dogs. Searches were conducted in PubMed, SciELO, SCOPUS, and Google Scholar using the descriptors “canine visceral leishmaniasis,” “Brazil,” and “prevalence,” including publications from 1963 to 2025 that employed ELISA or molecular diagnosis in domiciled, stray, or semi-domiciled dogs. Of the 747 articles identified, 190 were eligible, covering 117 municipalities (3.43% of the national total). In the histopathological study, skin samples from dogs with positive diagnoses were collected on day 0 (D0) and day 45 (D45) after treatment with marbofloxacin associated with allopurinol and domperidone. Samples were stained with Hematoxylin–Eosin and evaluated for alterations in the epidermis, dermis, monocytic system, skin appendages, vasculature, and pigmentation. CVL prevalence ranged from 0% to 73%, with a mean of 20.76%. A predominance of lymphoplasmacytic and histiocytic infiltrate was observed, with a slight reduction in inflammatory intensity after treatment.