Water-Soluble Vitamins (Riboflavin, Niacin, Pantothenic Acid) in Dogs with Chronic Liver Disease vs. Healthy Controls

Background: Water-soluble vitamin deficiencies are common in human chronic liver disease (CLD) due to impaired metabolic pathways. Vitamins B2 (riboflavin), B3 (niacin), and B5 (pantothenic acid) assume critical roles in hepatic and lipid metabolism and may exert hepatoprotective effects. In canine CLD, data beyond cobalamin are sparse, and no guidelines currently endorse B-vitamin supplementation. Methods: This case–control study analysed 66 stored serum samples from client-owned dogs with CLD and 50 from healthy blood-donor dogs. CLD diagnosis required persistent (>2 months) elevation of at least two liver enzymes (ALP, GGT, AST, ALT) and ultrasonographic evidence of CLD. Serum vitamin concentrations were quantified by LC-MS/MS (ng/mL). Results: Vitamin B2 was significantly lower in CLD dogs versus controls (median 48.4 vs. 85.5 ng/mL; p = 0.002). No significant difference was observed in B3 levels (p = 0.25). Vitamin B5 concentrations were significantly higher in the CLD group (median 176.5 vs. 116.1 ng/mL; p = 0.003). Conclusions: Reduced B2 may reflect impaired hepatic processing or absorption in canine CLD. The presence of normal or elevated B3 and B5 may relate to alternative metabolic pathways. This constitutes the first study assessing B2, B3, and B5 in canine CLD, underscoring riboflavin’s potential interest in CLD dogs.