Altered Iron Metabolism in Dogs with Naturally Occurring Cardiac Disease

Area of Science:

• Veterinary Cardiology
• Canine Internal Medicine
• Iron Metabolism

Background:

• Cardiac disease is a leading cause of death in dogs.
• Iron deficiency in humans with heart disease worsens symptoms and quality of life, independent of anemia.
• Iron metabolism in dogs with heart disease is poorly understood, often only considered in relation to anemia.

Purpose of the Study:

• To investigate iron metabolism and its regulatory pathways in dogs with cardiac disease.
• To determine if dogs with cardiac disease exhibit an iron-restricted phenotype.
• To assess the relationship between iron handling, inflammation, and cardiac disease severity in dogs.

Main Methods:

• Evaluated hematologic indices, serum iron, iron-binding capacity (TIBC, UIBC), ferritin, hepcidin, ceruloplasmin, C-reactive protein, and albumin in 61 dogs.
• Included healthy controls, dogs with compensated cardiac disease (CCD), and dogs with acute decompensated congestive heart failure (ADCHF).

Main Results:

• Dogs with cardiac disease showed systemic inflammation, reduced hematocrit, increased red blood cell distribution width, and decreased circulating iron.
• Both cardiac groups had reduced total and unsaturated iron-binding capacity (TIBC, UIBC), indicating decreased iron transport.
• Hepcidin levels were lower in CCD dogs and not elevated in ADCHF dogs, suggesting atypical iron regulation.
• In ADCHF dogs, iron-binding capacity correlated with cardiac remodeling, and inflammation markers linked to iron parameters.

Conclusions:

• Dogs with cardiac disease display systemic inflammation and altered iron metabolism, characterized by reduced iron availability and transport capacity, irrespective of anemia.
• Iron dysregulation in canine cardiac disease appears complex, with hepcidin regulation not following a typical inflammatory pattern.
• Findings suggest a significant interaction between inflammation, iron handling, and cardiac disease severity in dogs, highlighting potential therapeutic targets.