Objective: To evaluate plasma concentrations and urinary excretion of vasopressin and cortisol and urinary excretion of catecholamines in dogs with dilated cardiomyopathy (DCM).
Animals: 15 dogs with clinical signs of DCM, 15 dogs with preclinical DCM, and 15 control dogs.
Procedure: Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs. Blood and urine samples were collected.
Results: Plasma concentration of vasopressin and the urine cortisol-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM and dogs with preclinical DCM, compared with control dogs. Plasma vasopressin concentration was significantly higher in dogs with clinical signs of DCM, compared with dogs with preclinical DCM. Urine vasopressin-to-urine creatinine ratio was significantly increased in dogs with clinical signs of DCM, compared with dogs with preclinical DCM and control dogs. Urine epinephrine-to-urine creatinine ratio and urine norepinephrine-to-urine creatinine ratio were significantly increased in dogs with clinical signs of DCM, compared with control dogs. Plasma concentration of cortisol and urine dopamine-to-urine creatinine ratio did not differ significantly among groups.
Conclusions and clinical relevance: According to this study, the neuroendocrine pattern is changed in dogs with preclinical DCM. These changes are even more pronounced in dogs with clinical signs of DCM. Analysis of concentrations of vasopressin, cortisol, and catecholamines may aid in identification of the clinical stages of DCM. These findings may also provide a basis for additional studies of the possible beneficial effects of vasopressin antagonists and beta-adrenergic receptor antagonists in the treatment of dogs with congestive heart failure and DCM.