Safety Assessment of Repeated Oral Administration of Tolfenamic Acid in Japanese Quails: Haematological, Biochemical and Histopathological Evaluations

OBJECTIVE: This study evaluated the safety profile of tolfenamic acid following repeated oral administration in Japanese quails (Coturnix coturnix japonica) at doses of 2 and 8 mg/kg every 12 h for 7 days. METHODS: The 42 quails were randomly assigned to three groups. The first group (n = 6) received saline orally every 12 h for 7 days. The second (n = 18) and third (n = 18) groups were administered tolfenamic acid at doses of 2 and 8 mg/kg, respectively, orally every 12 h for 7 days, totalling 14 doses. The safety profile of tolfenamic acid was evaluated by haematological, biochemical and histopathological parameters. RESULTS: Haematological analysis revealed no significant differences across groups, except for a decreased mean corpuscular haemoglobin concentration in the 8 mg/kg group. Biochemical assessments indicated stable liver and kidney function markers, as no significant changes were observed in alanine aminotransferase, aspartate aminotransferase, total cholesterol, albumin or creatinine levels. However, histopathological examinations showed significant liver changes, including hydropic degeneration and bile duct proliferation, as well as renal tubular epithelial degeneration, particularly in the higher dose group. Notably, lymphoid tissue depletion was observed in the spleen of treated birds. CONCLUSION: These findings indicate that tolfenamic acid administration does not adversely affect haematological or biochemical parameters. Although biochemical parameters remained normal, histopathological changes such as tissue damage may indicate early or subclinical injury that could impair organ function over time. These microscopic alterations might lead to long-term health issues in quails, even without biochemical abnormalities. Therefore, cautious dosing and regular tissue monitoring are important when using tolfenamic acid.