Managing Canine with Heart Failure
Heart failure occurs in older pets as a result of several forms of heart disease. Commonly, small breed dogs develop heart failure as a result of scarring of the main valve of the heart (mitral valve disease) and larger dogs develop heart failure as a result of an acquired weakness of the heart muscle (dilated cardiomyopathy).
Signs of heart disease (such as a heart murmur) may be present for many years with your pet showing few signs of ill health. However, most pets with significant underlying heart disease will be unable to undertake extreme exercise, may have a cough from time to time and will have difficulty controlling their body temperature when it is very hot.
THINGS TO AVOID
· Salt loading e.g. salty snacks such as crisps or bacon
· Irregular or extreme exercise. Regular moderate walks to keep fit are very good.
· Exposure to excessive heat, such as long car journeys in the summer.
In the early stages of heart disease associated with valve degeneration no treatment has been shown to be beneficial. However, in large breed dogs with cardiomyopathy appropriate medication may prevent the development of symptoms for months or years. However, heart disease is progressive. Eventually, the heart is unable to pump enough blood in a forward direction through the general circulation and blood dams up behind the weakened heart in the vessels of the lungs. This causes fluid to leak into the lungs (pulmonary congestion) and causes breathing difficulties. This is called congestive heart failure.
MEDICATION
If a heart patient shows signs of pulmonary congestion they may develop distressed breathing over a short period of time. We would normally hospitalise these patients until the congestion is relieved. Afterwards, we will begin treatment with the diuretic tablet frusemide (a water tablet that stops congestion of the lungs) together with another tablet to reduce the load on the heart. Once treatment with diuretics begins, your pet will require ongoing treatment for life. It is vitally important that your pet does not run out of tablets so please ensure that you renew any prescriptions in good time.
MONITORING
Because the underlying heart disease will slowly worsen, we normally re-assess heart patients at intervals of no more than 3 months. Between re-checks you can help to monitor the response to treatment. If the treatment is effective:
· Your pet will have a good appetite and will be capable of moderate exercise.
· Coughing should not be excessive. Some coughing is inevitable because the heart will have enlarged and will be pressing on the larger airways.
· If you count your pet’s breathing rate while they are resting or asleep, they should always be breathing at a rate of less than 30 breaths per minute.
· If you feel your pets heart beat on the side of the chest, the heart rate should be less than 170 beats per minute. Usually, the rate will vary between 96-144 per minute and will be a little irregular.
If your pet is not responding in the expected manner, please contact the vet. All patients that show signs of congestive cardiac failure have severe heart disease and may develop problems in addition to the primary complaint.
DECOMPENSATION
After a period of time on heart medication, it is likely that the patient will again show signs of pulmonary congestion – this is called decompensation. This occurs because the underlying heart disease has got worse over time. Fortunately, usually all that is required is to increase the dose of diuretics used or to alter the medications in other ways in order to restore your pet to health. Some pets may decompensate several times over several years but still enjoy extended periods of good health between times.
LASTLY
With effective treatment, a pet with heart failure has about a 40% chance of dying in any one year. We expect that many of our heart patients will survive in good order for several years after they begin heart medication. However, all patients that require medication have severe underlying heart disease and are at risk of sudden death from many causes.
