by Barry B. Burtis D.V.M.
Congestive Heart Failure and Quality of Life
It is estimated that approximately 10% of dogs will develop some form of heart disease. Most types of heart disease are not reversible. Patients who have heart disease will often develop problems that affect their quality of life. One of the diseases where this happens is called congestive heart failure.
Dilated cardiomyopathy and mitral valve insufficiency are the two most common heart disorders that lead to congestive heart failure. With dilated cardiomyopathy it is the heart muscle that fails. The muscle becomes distended and flabby and the heart loses its ability to effectively act as a pump and move blood through the body. This disease is most common in Doberman pinschers and several other giant breeds - Scottish deerhounds, Irish wolfhounds, Great Danes and Saint Bernards.
The mitral valve is one of the heart valves that directs the blood flowing from one chamber to another inside the heart. If for some reason this valve does not fit together snugly when it closes, blood flow through the heart will be adversely affected. If this happens, again the heart as a pump may eventually fail because it is unable to compensate for the faulty valve function. This disorder is often associated with aging in a number of different breeds.
When congestive heart failure occurs, for whatever reason, problems will result. These problems happen because the heart is unable to move the blood forward through the body. When this happens there is also a damming back of blood behind the heart pump. Fluid will begin to seep out of blood vessels and into other body tissues.
How is quality of life impaired in dogs with congestive heart failure ? There are a number of ways. With reduced outflow of blood from the heart, kidney function is often affected. With loss of kidney function nausea, vomiting, loss of appetite, malaise and diarrhea may result. The bowel can also be affected by a less effective supply of blood and that can lead to reduced absorption of food nutrients, diarrhea, nausea, vomiting and loss of appetite. With ineffective blood supply to muscles, weakness and lethargy can be expected. Lethargy may also be caused because blood supply to the brain will also be changed with poor heart function.
Additionally, with reduced cardiac efficiency significant problems are likely to occur in the respiratory system. Dogs may develop a cough, experience difficult, laboured breathing and suffer loss of sleep as well. Also, some of the drugs used to treat dogs with congestive heart failure, can have unpleasant side-effects. Excess diuretics and digitalis would be examples of such drugs.
How do we try to offset some of these effects on the quality of life of dogs with this kind of heart disease ? Heavy exercise is usually not good for a dog with this kind of heart disease. However, veterinary cardiologists often recommend short, easy, regular walks for the pet. Exercise, even in this restricted form, can have so many benefits in making life more pleasurable. Diet recommendations can have a major impact. Usually cardiac diets have restricted sodium levels to help lessen fluid accumulating in the lungs. This is beneficial, only if dogs still enjoy the food. If they do not, then perhaps other medications can be used to accomplish this and the dog can be allowed to eat something it really enjoys. I have talked before about how important enjoying food is to quality of life.
There are 2 medications that can greatly help almost all dogs with congestive heart failure. One of these are ACE inhibitors. They have been used for a number of years and have shown they improve the survival of patients and their quality of life. The other is a very new and recent arrival on the veterinary scene. The drug is pimobendan. Its trade name is Vetmedin. It appears to be the most exciting drug to have come along for use in dogs with congestive heart failure for a long time. It has been shown to improve quality of life for dogs with this disease by improving their ease of breathing, increasing their exercise tolerance, improving their outlook and demeanor and improving their appetite and weight gain. Patients feel better, they feel better faster and they feel better longer ! Moreover, these positives are achieved with virtually no toxic or ill-effects from the drug. This is good news for dogs with this disease, for their owners and for their veterinarians.