First report of a cat (Felis catus) infected by Leishmania (Viannia) guyanensis from Southeastern Brazil.

Feline leishmaniasis is increasingly recognized as a disease affecting cats worldwide, with notable prevalence in regions surrounding the Mediterranean Basin and in Brazil. An approximately one-year-old domestic shorthair cat was presented with small papules and nodules (2 mm) on the nasal planum. Physical examination and routine blood analyses were normal. The cat tested negative for FIV and FeLV. Skin biopsies of the lesions were conducted, removing the nodules entirely due to their small size. The samples were submitted for histopathological and molecular analysis. Histopathology confirmed the presence of Leishmania amastigotes, while PCR-RFLP and Sanger sequencing of the hsp70 gene identified the infecting species as Leishmania guyanensis. The patient has since been under continuous clinical monitoring every six months, with no recurrence observed to date. This is the first documented case of L. guyanensis infection in a domestic cat, underscoring the need for improved diagnostic accuracy and a broader understanding of feline leishmaniasis.