Canine Congestive Heart Failure
The term "congestive heart failure" (CHF) is misleading. It does not mean that the heart has stopped functioning; it simply means that the heart is weakened, unable to meet the dog's circulation needs. When there is inadequate circulation, other vital organs, such as the liver, lungs, and kidneys may be affected, so the condition must be treated promptly. Fortunately, there are many treatments available to help dogs with CHF lead happy lives. Left untreated, however, strenuous exercise, certain medical procedures or other diseases may put a dog with heart disease at serious risk.
Causes of Canine CHF
There are many possible causes of CHF in dogs. Many are thought to be genetically linked. In large breeds, the cause of CHF is usually cardiomyopathy. In small breeds, CHF is most commonly the result of damaged valves which cause mitral regurgitation.
Signs of Canine CHF
There are several early warning signs that a dog, even a seemingly healthy, playful dog, has congestive heart failure. These may include:
- Decrease in activity level
- Tiring more easily than usual
- Coughing during exertion or when excited
- Difficulty settling down to sleep
In older dogs, these signs may be confused with normal signs of aging. As the disease process progresses, the dog may develop more serious indicators of congestive heart failure, including:
- Abdominal swelling
- Loss of appetite
- Rapid breathing
- Substantial weight loss
When the heart fails to pump efficiently, blood backs up into the organs and the increased pressure on the vein walls may cause fluid leakage in the lungs. When fluid accumulates in the lungs, a condition known as pulmonary edema, the dog develops an intermittent cough. At times, the dog may cough up a foamy red fluid. While pulmonary edema is caused by failure of the left ventricle (lower chamber of the heart), when the right ventricle fails, fluid leaks into the abdomen, accumulating there and resulting in abdominal swelling. This condition is known as ascites. Fluid may also accumulate in the legs.
During late-stage canine CHF, the dog has a rapid, faint, irregular pulse. Breathing is labored and the mucous membranes turn blue-gray. A dog at this stage of CHF can easily faint with overexertion or stress.
Diagnosis of Canine CHF
Canine CHF is primarily diagnosed through medical examination, chest X-rays and an echocardiogram. In some cases, other diagnostic tests may be used to rule out other diseases, such as heartworm.
Treatment of Canine CHF
When heart damage results from a congenital abnormality, it may be correctly surgically, hopefully before any permanent damage is done. If the cause of the condition is another disorder, the underlying disease must be addressed. Typically, treatment for dogs with CHF includes one or more of the following:
- Low-salt diet
- Restricted exercise
- Medication to improve heart function
- Medication to prevent cardiac arrhythmia
- Diuretics
- Coensyme Q (CoQ10)
- Potassium supplements
In certain cases of canine heart arrhythmia, a pacemaker may be implanted to normalize the heart rate. With proper treatment and regular monitoring, dogs with congestive heart failure can live comfortable lives for many years.