In The Bahamas, heart disease is a major cause of death in people, as it is in animals. In humans it is because of lifestyle challenges (smoking, diet, etc). In animals, the cause is usually hereditary, heartworms, age-related or degenerative. Middle-aged and older small dogs are most often affected. A number of conditions can adversely affect the function of the heart. Heart failure results when a damaged heart muscle is no longer able to move blood throughout the body. Without treatment, the dog will die. Disease prevalence severely increases with age.
Signs of heart disease vary from type-to-type, but many times the affected dog suffers exercise intolerance (becomes exhausted quickly), may act weak or have a bluish tinge to the skin and tongue from the lack of oxygen. In most cases of chronic heart failure, the dog's body retains fluid (edema), due to the body trying to compensate for reduced heart efficiency. The result is a retention of sodium and fluids, increased blood volume, constriction of blood vessels and increased blood pressure.
Heart disease has a cascading effect on the whole body and can lead to damage of other internal organs like the kidney, liver and lungs. When the left side of the heart fails, fluid collects in the lungs (pulmonary edema) and results in a cough, labored breathing and panting. Obesity complicates heart disease and makes it more difficult to treat, but some dogs suffer weight loss and seem to waste away. Dogs sit with elbows spread and neck extended while straining to breathe. They may even try to sleep in this position to ease respiration.
When the right side of the heart fails, fluid collects and swells the abdomen, accumulates beneath the skin, and/or fills the chest cavity. This fluid accumulation results in congestive heart failure. Usually, dogs suffering from heart failure will have a heart murmur. Many times, right heart failure develops as a result of the strain from an existing left heart failure.
Congenital heart disease may or may not be inherited and is quite rare. Patent ductus arteriosus is the most common, and is seen in poodles and shepherds. Congenital pulmonic stenosis and aortic stenosis are also conditions that are seen. Acquired heart disease, unlike congenital, develops over time, and is commonly due to other conditions like cancer, parasites (heartworm) or infectious disease (periodontal disease). Acquired valvular heart disease is considered a disease of old age, with about one third of all dogs over the age of 12 affected. It is most common in smaller breeds. The heart valves simply begin to wear out and leak blood backwards instead of pumping it all forward. This puts extra strain on the heart. Dilated cardiomyopathy may also cause heart valve problems. This is a disease of the heart, rather than the valves. The heart loses the ability to adequately contract and pump blood out. The heart itself enlarges, but becomes flaccid, and the muscle walls become thin. This is usually a hereditary problem and is seen in boxers, cocker spaniels and Dobermans.
Diagnosis of heart disease is made using x-rays, ultrasounds and electrocardiograms (EKG) that pick up irregular heart rhythm. Dogs with heart disease due to heartworms can be cured if diagnosed and treated early. Dogs with valvular heart disease can often be helped with drugs that improve the heart performance and reduce flow accumulation. A diuretic drug like Lasix forces the kidney to eliminate excess salt and water. Vasodilation drugs like Enalapil help open the lungs and control congestion. Digoxin may help improve heart muscle performance in certain types of heart disease.
Click here to read more at The Nassau Guardian
