Relationship of serum leptin concentration with pituitary‐dependent hyperadrenocorticism and cholestatic disease in dogs

OBJECTIVES: To measure serum leptin concentration in dogs with pituitary‐dependent hyperadrenocorticism and varying degrees of cholestatic disease and determine whether serum levels differed between dogs with pituitary‐dependent hyperadrenocorticism and those with gall bladder mucocoele. MATERIALS AND METHODS: Client‐owned healthy dogs (n=20), dogs diagnosed with gall bladder mucocoele (n=20) and dogs diagnosed with pituitary‐dependent hyperadrenocorticism (n=60) were enrolled. Only dogs of normal body condition score were included. Dogs with pituitary‐dependent hyperadrenocorticism were divided into three groups according to the severity of cholestatic disease: normal gall bladder (n=20), cholestasis (n=20) and gall bladder mucocoele (n=20). Serum leptin levels were measured using sandwich enzyme‐linked immunosorbent assay. RESULTS: Serum concentrations of leptin were similar between dogs with gall bladder mucocoele and those with pituitary‐dependent hyperadrenocorticism accompanied by gall bladder mucocoele; these concentrations were significantly higher than those in healthy control dogs. In dogs with pituitary‐dependent hyperadrenocorticism, circulating leptin concentration significantly increased with the severity of cholestasis: higher in the cholestasis group than the normal gall bladder group and higher in the gall bladder mucocoele group than the cholestasis group. CLINICAL SIGNIFICANCE: Elevated circulating leptin concentration was associated with canine pituitary‐dependent hyperadrenocorticism and gall bladder mucocoele. Homeostatic imbalance of leptin concentration might be associated with severity of cholestatic disease in pituitary‐dependent hyperadrenocorticism.