In conclusion, in this study, we demonstrated that an increase in serum leptin concentrations and hyperlipidemia (hypercholesterolemia or hypertriglyceridemia) is associated with the occurrence of cholelithiasis in dogs, and the results of this study suggest that the homeostatic imbalance of these parameters may affect the pathogenesis of gallstones. Here, LEP is linked to familial hypercholesterolemia.