The function of a healthy heart is to supply oxygenated blood to the body. First, it pumps blood to the lungs to pick up oxygen molecules, and pushes that oxygenated blood out to all of the organs and parts of the body. Once the oxygen is delivered, the blood returns to the heart to start the process all over again. In a dog with heart failure, the dog’s heart is unable to sustain and maintain the circulation that is required to meet the needs of the body. When this happens, fluid accumulates, the blood is backed up, and all of the systems of the bod suffer. Heart failure must be treated immediately to increase the dog’s chance of survival.

The signs of heart failure are usually subtle, and onset may come quickly or slowly, depending upon the cause of the problem.

Many things may cause heart failure: inherited heart abnormalities, environmental stress, injury or trauma to the heart, breed dispositions, ingestion of toxins, congenital abnormalities in the chambers or valves, and infection. The main causes of heart failure are chronic valve disease, nutritional conditions, and arrhythmias.

Heart failure is one of the most serious conditions that can affect a dog, but there are few things you can do to prevent it. One way to prevent it is to make sure your dog does not become obese; feed it a high-quality food and monitor its weight to ensure you are not over- or underfeeding it. Adjust food amounts accordingly to maintain a healthy weight. Combined with a good diet, regular exercise helps keep dogs in good health and maintains a healthy weight. Heartworm treatment helps prevent heartworm-caused heart failure.

The symptoms of heart failure can be very subtle, or may appear to be caused by something else. Dog owners who are in tune with their pet’s health will often realize something is wrong; if you notice any of the signs listed below, please get your dog to the vet immediately. Early diagnosis of heart failure will often mean the difference between life and death for your dog.

Depending on whether the left or the right side of the heart is affected, the symptoms may change. Right-sided failure, also called “backward failure,” causes lethargy or weakness, abdominal distension, and exercise intolerance. Left-sided failure, called “forward failure,” causes bluish gums and skin, breathing difficulties, coughing, and lethargy or weakness.

A dog with heart failure may appear to be less active than normal, may start to eat less, lose weight, tire easily, or exhibit rapid breathing or panting – even when the dog is at rest. Coughing may worsen as the dog lies down. Your dog may exhibit diarrhea or vomiting, or have a pot-bellied look, which is caused by fluid retention. It may seem fidgety or restless, uncomfortable, or just “not right.”

Dogs at Risk
Heart failure can happen in any dog breed, and in either gender. Dogs are usually at least five years old before they start to show signs, but younger dogs may develop heart failure as well. Dogs with congenital heart defects should be carefully monitored so that signs of heart failure are detected early and treated aggressively. Those animals with genetic heart problems are more at risk.

Testing and Diagnosis
When a vet suspects your dog has heart failure, he or she will take a complete history and will do a basic exam. He or she will likely perform an x-ray to check for an enlarged heart. Other tests include an echocardiograph to look at the heart’s blood flow and function, an electrocardiogram (EKG) to check the electrical activity, and urinalysis or blood tests. The vet should check for fluid build-up, heart murmur, or other evidence of heart failure.

Treatment and Prognosis
The symptoms of heart failure may range from mildly uncomfortable to life-threateningly painful. First off, the goal is to make the dog more comfortable. This may involve reducing fluid retention, administering oxygen, administering a diuretic, improving circulation, and removing fluid from around the heart and lungs. The dog should be kept in a soothing, calm, darkened environment, and not placed under undue stress.

Exercise should be kept to its tolerance. The dog’s diet should be low-sodium to reduce water retention, and the intake should be monitored to maintain a healthy weight, or reduce its weight if it is obese. Like with all dogs, it should have constant access to clean drinking water.

Some medications that may be prescribed include ACE inhibitors, Lasix (diuretic), or those that work to increase the heart’s contractility.

The progression of the heart failure will dictate the prognosis. Early stages can be treated, once the underlying cause is treated. More advanced cases – where organs have suffered as a result of insufficient blood supply – have a serious-to-grave prognosis.