Systemic CD3+ T-Cell Lymphoblastic Leukemia in a Bearded Dragon (Pogona vitticeps): Clinical, Therapeutic, and Pathological Findings.

A three-year-old male bearded dragon (Pogona vitticeps) exhibited acute anorexia. Biochemistry revealed mild hyperproteinemia (88 g/L) and elevated liver enzymes (ALT 60 U/L, AST 272 U/L), while the hematology report showed marked lymphocytosis. The animal had been clinically normal at a routine examination 10 months earlier. Based on the clinical and laboratory findings, acute lymphoblastic leukemia was suspected. Treatment was initiated with methylprednisolone (1 mg/kg PO q24h), marbofloxacin (10 mg/kg IM q24h), and lomustine (80 mg/m2 PO q14d), calculated according to reptile-specific body surface area formulas. A transient stabilization was followed by sudden deterioration on day 3, characterized by hematemesis and severe respiratory distress, leading to spontaneous death. A complete necropsy including histopathology and anti-CD3 immunohistochemistry revealed disseminated infiltration of neoplastic T-lymphocytes throughout all major visceral organs and confirmed the diagnosis of T-cell lymphoblastic lymphoma/leukemia (L/L). This case represents a rare report of systemic acute lymphoblastic L/L in a bearded dragon and underlies the importance of comprehensive diagnostics in reptiles with non-specific clinical signs and the challenges in the treatment of neoplastic diseases in exotic species.