Think about the heart as a pump. Its job is to pump blood to the lungs and body 24 hours a day, seven days a week. It can't take a break and sometimes has very high demands put on it, like during exercise.
What types of heart problems do dogs have?
Heart disease is either congenital (present at birth) or acquired. Acquired heart disease develops sometime throughout life, often as a senior, and is typically due to genetics rather than diet with one exception: Some dogs develop dilated cardiomyopathy from eating diets deficient in taurine. Taurine is an amino acid that is supplemented in all major commercial dog foods.
Here is a brief summary the common forms of heart disease in dogs:
Congenital heart disease
PDA -- When a vessel doesn't close properly after the puppy is born and blood goes the wrong direction.
Septal defects -- When there is a hole in the wall of the heart between chambers.
Aortic or pulmonic stenosis -- When the exit pathways for blood leaving the heart are narrower than they should be.
Acquired heart disease
Valvular disease -- A leak occurs because a valve didn't close properly.
Dilated cardiomyopathy -- When the heart walls are stretched thin like a balloon.
Arrhythmias -- An irregular heart beat.
Pericardial disease -- When fluid builds up in the sac around the heart.
Heartworm disease -- Worms in the heart cause a blockage of normal blood flow.
How do I know if my dog has heart disease?
Heart disease can have no visible symptoms but your veterinarian may hear a murmur or abnormal rhythm on physical exam. When severe enough, heart disease leads to difficulty breathing, blue or gray gums, coughing, weakness or fainting episodes. If your veterinarian suspects heart problems he or she will probably discuss doing tests such as chest X-rays, and electrocardiogram or an echocardiogram (ultrasound of the heart).
How is heart disease treated?
Treatment is based on the underlying problem and either involves giving medications or performing a procedure. A low sodium diet is recommended for most types of heart disease. Medical treatment consists of diuretics (to dry up fluid that has overflowed the system), anti-arrhythmic medications or other medications. Procedures or surgeries for heart disease are less common and performed by a cardiologist or surgeon. These include placing a stent, coil, balloon dilation, placing a pacemaker and open chest surgery.
Some forms of heart disease are regularly treated and managed by veterinarians in general practice. For more complex heart problems there are board specialized cardiologists who practice at specialty hospitals or veterinary universities.
Next month I'll talk about heart disease in cats, because of course, they have their own set of problems!