Current Challenges in the Association between Canine Leishmaniasis and Malignant Disorders

Abstract

Neoplasms in dogs are estimated to account for up to 83% of all canine malignancies, while canine leishmaniasis is endemic and highly incident in areas like Brazil, east Africa, and India. The worldwide incidence of both diseases may indicate the presence of these two pathologies in the same tissue sample as eventual cases. However, a relationship between leishmaniasis and malignant disorders has been postulated in human and veterinary medicine. Depending on several direct or indirect factors, leishmaniasis can affect the clinical manifestation, diagnosis, therapeutic protocols, and the outcome of various malignant disorders. In addition, the similarity of the clinical presentation of cutaneous or visceral leishmaniasis with the clinical signs observed in many tumors may lead to misdiagnosis. Clinical cases of co-localization of Leishmania parasites and tumor cells in dogs were more associated with transmissible venereal tumors than histiocytic tumors, non-histiocytic lymphoma, or squamous cell carcinoma. This chapter reviews the circumstances involving canine leishmaniasis and malignant disorders, and the current challenge that the association between them represents to misdiagnosis or tumor-promoting potential of leishmaniasis, providing an overview of dog cases.