Dog - Heart Disease - Congestive Heart Failure

What is congestive heart failure?

When the heart fails to pump sufficient blood around the body it tries to compensate by attempting to increase the rate and the strength of the contractions. This can improve the situation and symptoms virtually disappear. Without treatment the condition slowly gets worse as the heart weakens. This results in blood not being cleared from the organs and tissues leading to the signs of congestive heart failure (CHF). The animal is said to have decompensated.

What are the signs?

Clinical signs depend on whether the dog has left or right side heart failure. This usually involves failure of the valves of the heart although sometimes the muscle can be involved.

Right sided heart failure usually involves less blood being pumped through the lungs for oxygenation since some returns through the leaky right valve back into the right auricle, thus preventing blood from being returned from the general circulation. This becomes congested resulting in accumulations of fluid in the abdomen or the chest cavity interfering with organ function in these areas. The abdomen usually becomes enlarged due to the fluid. This is dropsy (ascites). The pooling of blood in the veins results in further leaking of fluid through their thin walls leading to swelling of the limbs in severe cases.

Left sided heart failure similarly results in blood leaking back through the mitral valve into the left auricle resulting in fluid building up in the lungs. This causes pulmonary oedema (fluid on the lungs) resulting in coughing and breathing difficulties.

Irrespective whether left or right sided congestive heart failure, the result is similar. Circulation of blood is impaired resulting ultimately in failure of major body organs.

Are there any other causes of CHF?

Apart from valvular disease and cardiomyopathy (heart muscle disease), irregularities of rhythm and narrowing of some of the major blood vessels can also cause the condition.

What are the usual signs?

Coughing, ascites (dropsy), exercise intolerance and general lethargy are the usual signs. These are often accompanied by weakness and weight loss although the latter may be partially concealed by the huge abdomen due to the dropsy (ascites). The normally pink coloured mucous membranes (e.g. inside the lips or under the eyelids), may become pale or even appear bluish.

How is the condition diagnosed?

With any heart condition, accurate diagnosis leads to a much better treatment and thus a much happier, if not entirely cured, patient. Therefore a ‘full work-up’ will include blood and urine tests to establish there are no problems in other organs, e.g. the liver and kidneys; auscultation, (listening to the heart with a stethoscope) which detects abnormalities of the valves (murmurs) and also irregular rhythms. Radiographs (x-rays) will give an indication of changes in heart size or shape as well as the state of the lungs; e.g. fluid accumulation etc. Ultrasonography allows us to examine the heart in motion and, if necessary, take measurements which give a very accurate diagnosis, often without even the need for patient sedation with this technique.

Are these tests expensive?

A full work up can cost several hundred pounds but, depending on the condition, and its severity, sometimes only selected tests are necessary.

Since my dog is not insured, is it possible to avoid some of these tests and spend the money on treatment?

Accurate diagnosis gives us a much better guide to the type and extent of treatment necessary. Today there is a wide selection of drugs that can be used to treat congestive heart failure and treatment regimes can be tailored for each animal.

With correct treatment, although this in most cases is not curative it makes the dog more comfortable. Dogs, like many animals, may be able to live normal lives often for months or years. If you would like to discuss this further, please do not hesitate to contact us.