Congestive Heart Failure in Dogs
Congestive heart failure in dogs may be considered a silent disease. Because of the heart's ability to compensate even though weakened, the disease may go unnoticed for many months and in some cases even years. Then, out of the blue, the dog or cat may begin exhibiting worrisome symptoms that will be brought to the attention of the veterinarian.
A normal heart functions very well and is able to provide adequate quantities of blood to all the tissues and organs of the body. In congestive heart failure, the heart is no longer able to pump blood effectively, negatively affecting circulation to the body and causing organ impairment. Liver, kidneys, lungs, and other vital organs will ultimately be affected as well.
The causes of congestive heart failure may be various. The pet may have been born with a heart defect, in which case, the condition may be considered congenital. The presence of heartworms in the dog's heart may cause sufficient damage to cause heart failure. Toy- and small-breed dogs in general are prone to chronic valvular disease, which may ultimately cause congestive heart failure. Large- and giant-breed dogs on the other hand, have a tendency to develop cardiomyopathy, which also may cause failure of the heart organ.
Symptoms may be moderate and in some cases barely noticeable at the dieases's early stages. The affected pet may appear to be more tired than usual upon exertion. A dog may pant more during walks, require a break, or come home more tired than usual, breathing fast and panting. A cough may appear as well during exertion. However, as the disease advances, the pet may cough during the night a few hours after the pet lays down to sleep. This is due to fluid pooling in the lungs because of the heart's inability to work efficiently. Also the dog may appear restless prior to going to sleep, pacing around and acting uncomfortable.
These symptoms may be subtle, and, since congestive heart failure appears often in senior pets, they are easily confused as normal cases of aging. Once the disease advances, more specific symptoms may arise and the pet may refuse to eat, lose weight, and breathe rapidly. Also, because the heart does not function properly, fluids will accumulate in the legs (leg edema).
When the left ventricle of the heart has halted from functioning, the dog will cough up a pink, bubbly fluid, a condition known as pulmonary edema. Fluids will also tend to leak in the abdomen, causing a condition called ascites, and in the chest, causing a condition known as pleural effusion. Affected pets will experience swelling in the abdomen, chest, and legs. A pet at the end stages of heart failure will have labored breathing and sit in a characteristic position with the head extended and elbows spread apart. Because circulation of blood is severely impaired, the gums will be bluish-gray. The pet may collapse.
The veterinarian will inspect the pet, listen to the heart and lungs, and order some specific tests. A heartworm test may be run via blood sample to rule out heartworm disease. Chest x-rays or an echocardiogram may be ordered. The pet's blood pressure may be monitored.
Affected pets will be prescribed diuretics to remove excessive fluids and reduce the workload of the heart. If pleural effusion is present, a procedure called thoracocentesis may be required. Such a procedure consists of inserting a needle into the chest cavity and draining out some fluid. Nitroglycerin may be prescribed to act as vasodilators. If there are arrhythmia, medications such as Digitalis may be prescribed. A special diet low in salt is required. Most commercial pet foods have high levels of sodium. Therefore, prescription diets may be required such as Hill's H/d Purina CV or Royal Canin EC. Potassium supplements are often prescribed because some diuretics tend to lower potassium levels.
When treated early, supportive care may prolong the pet's life, even by years. Dogs will be able to lead a more comfortable life. However, routine check ups will be required to monitor effectively the condition.