Long-term follow-up of a case of feline leishmaniosis treated with a combination of allopurinol and meglumine antimoniate.

A 9-year-old domestic cat with feline immunodeficiency virus (FIV) was diagnosed with feline leishmaniosis (FeL) after presenting with alopecia, ulcerative skin lesions, and upper respiratory tract signs. The diagnosis was confirmed through biopsy and serology, revealing high anti-Leishmania antibody titers. Treatment with allopurinol and meglumine antimoniate led to quick and complete clinical improvement. However, a relapse occurred when allopurinol was briefly stopped, and suspected acute kidney injury necessitated a reduction in the allopurinol dose. The cat remained clinically well for nearly 24 months before being euthanized due to worsening cardiac disease. This case highlighted a rare successful treatment of FeL, with potential nephrotoxic effects from long-term allopurinol use, and suggested the need for further studies on the relationship between leishmaniosis and heart failure in cats.