Serum Liposoluble Vitamins (A, D, E) in Dogs with Chronic Biliary Tract Diseases Versus Healthy Dogs

Humans with chronic biliary tract disease (CBTD) have low serum liposoluble vitamins (A, D, E). Few studies have been performed in veterinary medicine to evaluate whether vitamins vary in canine CBTD. This study aimed to compare liposoluble vitamin between CBTD and healthy dogs. A total of 84 client-owned dogs with CBTD and 50 healthy dogs were included. CBTD diagnosis was based on clinical, blood biochemistry and abdominal ultrasound. Dogs with CBTD were divided into subgroups according to their cholestasis ultrasound severity. To measure vitamin concentrations, leftover serum samples were used. The 25-hydroxyvitamin D, α-tocopherol, and retinol, respectively, vitamin D, E, and A metabolites, were measured with HPLC. Both, 25-hydroxyvitamin D and α-tocopherol were significatively lower in CBTD than in healthy dogs. In contrast, retinol was higher in CBTD dogs. In CBTD dogs, no significant differences in vitamin concentrations considering ultrasound severity were found. Presence of biliary disease in dogs results in lower blood vitamins D and E, and higher vitamin A concentration. Lower vitamins D and E concentration could reflect a possible lipid malabsorption. The higher concentration of vitamin A could be in line with recent human studies, where retinol increases as an expression of dysregulated homeostasis during chronic liver disease.