A dog's cough can be caused by any of several health problems. The most basic reasons for coughing in dogs include tracheal irritation, allergy and kennel cough, while more serious conditions include chronic valvular disease and cardiomyopathy. Valvular disease affects the heart valves and causes lung congestion, while dilated cardiomyopathy is an enlargement of parts of the heart and thinning of the ventricle walls. Both of these conditions can result in heart failure for a dog. If your dog develops any type of cough, consult an experienced veterinarian to determine whether you have cause for concern.
The coughing that signifies potential heart congestion occurs commonly after exercise or at night and may be accompanied by rapid breathing and bringing up of saliva with traces of blood. A moist-sounding cough usually indicates congestion in the airways or lungs, which results from the pressure of an enlarged heart on the organs. Gurgling, gagging and choking while coughing can be indications of reduced heart valve function that causes blood to be ejected backwards into the heart. Coughing and retching are symptoms of both valvular disease and cardiomyopathy.
Veterinarians base their diagnoses of heart disease on a number of factors, including the sound of a dog’s cough. Certain breeds are predisposed to heart conditions, with dilated cardiomyopathy being found more often in males of large and giant breeds and valvular disease common to small and toy breeds. To diagnose your dog’s cough, the veterinarian will need to evaluate the pattern and frequency of the coughing, examine any fluids produced by the cough, and analyze your dog’s blood and urine. He may also use X-rays, electrocardiogram and magnetic resonance imaging to get a clear view of the dog's heart and lungs or a scope to examine the dog's respiratory tract.
When a veterinarian identifies the reason for the coughing as a heart condition, the dog will require treatment specifically formulated for the illness. For example, a dog with dilated cardiomyopathy will receive medication aimed at strengthening the heart muscle and preventing fluid from building up in the lungs and abdomen. Medications that he may prescribe include Digoxin, which helps to strengthen heart contraction, and nitroglycerin-based formulas that dilate the veins to help reduce congestion. This treatment will both relieve the coughing and help to manage the dog’s heart condition.
Once a dog is diagnosed and treatment for heart disease begins, the outlook depends on the severity of the disease, the age and health of the dog at the time of diagnosis, and the quality of treatment he receives. With chronic valvular disease, the illness progresses in spite of treatment, but its effect can be managed and the dog can live for several years. With dilated cardiomyopathy, a dog with excellent medical treatment and control can live for a year or more, but sudden cardiac arrest can lead to unexpected death without warning.
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