Acute Congestive Heart Failure in Dogs

Congestive heart failure can be a devastating disease for dogs. When it strikes, it becomes important for caregivers to understand that their dog's heart is no longer functioning and what they can do to make the dog more comfortable.

  1. Types and Symptoms

    • Dogs, like humans, have a four-chambered heart consisting of two atria on top and two ventricles on the bottom. When the heart is unable to maintain a sufficient blood and oxygen supply to body tissues for normal function, heart failure occurs. There are typically two types of heart failure with two sets of concurring symptoms. Left-sided heart disease, which is more common, may include fainting spells, an early morning or late night cough, and difficulty breathing, either during exercise or while lying down. Fluid may accumulate in the lungs and heart arrhythmias are common. Right-sided heart failure can result in an enlarged liver and spleen, fluid accumulation in the lungs, cardiac sac, under the skin and in the abdominal cavity. Abnormally high blood pressure will show in an extended jugular vein.

    Causes

    • There can be several causes for congestive heart failure in canines. The most commonly diagnosed cause is called "mitral" or valvular insufficiency, where the valves in the heart are not functioning well enough to allow sufficient back flow of blood from one valve to the other. This can happen with drug toxicities, enlargement of the heart muscle and/or valves, and inflammation or infection of the pericardial sac. Heartworm disease allows the adult heartworm to migrate through the blood to the right atrium and ventricle, and inhibit blood flow and increase blood pressure to result in heart failure. Cardiomyopathy is an enlargement and thickening of the heart wall resulting in impaired pump function.

    Diagnosis and Treatment

    • A veterinarian will use several methods to diagnose congestive heart failure in a dog including a comprehensive health history, chest radiographs, and possibly a cardiac ultrasound. If fluid is found in the lungs, chest or abdominal cavity, and the animal is in respiratory distress, a needle may be introduced into the cavity to draw off fluids. The dog will usually be placed on a diuretic to increase urine output and can also be given drug treatment such as digoxin or enalapril to regulate heart arrhythmias and increase heart function. A sodium-restricted diet may be recommended at this point with owners urged to restrict exercise and not let the animal get too excited.

    Considerations

    • Congestive heart failure is more prevalent in some breeds of dogs including Dobermans, Irish wolfhounds, boxers, Afghans, Saint Bernards, Newfoundlands and Old English sheepdogs. It has also been seen in American and English Cocker spaniels. Heart failure is mainly a disease of older, male, large or giant breed dogs and is rarely found in dogs weighing less than 25 pounds.

    Warning

    • This is almost always a fatal disease for dogs with most dying within six months to two years after diagnosis. The goal of treatment is palliative care--increasing cardiac output and decreasing fluid accumulation so that the animal is more comfortable. At this point, quality of life is usually the prime consideration for veterinary professionals and owners alike.