CHALLENGES IN THE DIFFERENTIAL DIAGNOSIS BETWEEN INFECTIOUS AND NEOPLASTIC PROCESSES IN FELINE FeLV-POSITIVE PATIENTS: A CLINICAL EXPERIENCE REPORT

Abstract

The differential diagnosis between infectious and neoplastic processes in felines, especially in animals positive for the feline leukemia virus (FeLV), represents a frequent challenge in veterinary clinical practice. This study aimed to reflect on the diagnostic difficulties in distinguishing between these conditions based on a clinical experience. This is an experience report conducted in a private veterinary clinic, involving a five-year-old, mixed-breed, male feline, FeLV-positive, presenting a progressively evolving ulcerated cutaneous lesion. Clinical examination, microbiological culture with antimicrobial susceptibility testing, and fine-needle aspiration cytology were performed. Initially, the isolation of multidrug-resistant Enterococcus faecalis guided the clinical approach toward antibiotic therapy, resulting in partial improvement of the inflammatory condition. However, the persistence of the lesion and the emergence of nodular formations prompted cytological investigation, which revealed features consistent with malignant neoplasia, with cutaneous lymphoma as the main differential diagnosis. The lack of histopathological confirmation, due to financial constraints, was a limiting factor. The experience demonstrated that secondary infections may mask neoplastic processes, delaying definitive diagnosis, and reinforces the importance of continuous clinical reassessment and critical interpretation of laboratory findings.