Chronic Oral Administration of Phyllanthus niruri Extract Is Well Tolerated in Sheep: Hematological, Biochemical, and Histopathological Evidence

Phytogenic additives are increasingly explored as alternatives to synthetic feed additives in ruminant production, yet chronic organ-level safety evidence in sheep remains scarce. Phyllanthus niruri is widely reported to possess antioxidant, anti-inflammatory, and hepatoprotective activities, but its long-term safety in small ruminants has not been established. This study evaluated hematological indices, serum biomarkers of hepatic and renal function, and liver–kidney histopathology following eight weeks of oral supplementation with P. niruri extract in sheep. Twenty-four healthy male sheep (6–8 months) were randomly assigned to four groups (n = 6): control (0.5% CMC-Na) and extract-treated groups (5%, 10%, or 20% w/v), administered once daily at 1 mL/kg body weight. Hematology and serum biochemistry (AST, ALT, GGT, BUN, creatinine) were assessed at baseline and week 8, and tissues were examined histologically at study end. Total leukocyte counts increased significantly in all extract-treated groups; however, animals showed no clinical abnormalities and no histological evidence of inflammation. Other hematological indices and all serum hepatic and renal biomarkers remained within physiological limits with no adverse deviations. Histopathological evaluation revealed preserved hepatic and renal architecture without degeneration, necrosis, congestion, or tubular damage. Overall, chronic oral supplementation with P. niruri extract (5–20%) for eight weeks was well tolerated in sheep, supporting its safety as a candidate phytogenic additive, while further immunological profiling is warranted to clarify the leukocyte response.