Effects of and Milk Thistle Extracts on Biomarkers of Antioxidants Status and Liver Function in Healthy Dogs.

This study investigated the effects of and milk thistle seed extract (GB/MT) supplementation on antioxidant status, liver function, and general health in healthy dogs. Six French Bulldogs were enrolled in a crossover design and fed commercial diets supplemented with GB/MT at either 1 or 2 g/day for 21 days. Blood samples were collected at baseline (day 0), during supplementation (days 14 and 21), and after withdrawal (day 28) to assess serum superoxide dismutase (SOD), glutathione (GSH/GSSG), liver enzymes (ALT, AST, ALP), albumin, total protein, blood urea nitrogen, creatinine, triglycerides, and cholesterol. Results showed that GB/MT supplementation had no significant effect on antioxidant markers (SOD and GSH/GSSG) at either dose. However, both supplementation levels led to significant decreases in ALT and increases in serum albumin levels after 21 days. No significant differences were observed in other liver function or general health parameters. These findings suggest that GB/MT supplementation does not enhance antioxidant enzyme activity under non-stressed conditions but may support liver health by reducing liver enzyme levels and enhancing protein synthesis. The 1 g/day dose was found to be as effective as the higher dose, suggesting a cost-effective approach for maintaining liver function in dogs through dietary botanical supplementation.