Heart Disease in Pets

Heart disease can sneak up on all of us, so ensuring your pet has regular health checks may allow us to pick up problems before you are even aware there is anything going on.

About The Heart

The heart’s role is to pump blood, the vital nutrient rich liquid to our organs and muscles. To serve this function the heart is made up of 2 basic components:

The right side  receives blood that has travelled throughout the body and has had nutrients and oxygen removed.  The function of the right side is to refresh the blood with oxygen by pumping the blood through the lungs.

The left side serves to receive oxygenated blood from the lungs and then has the harder role of pumping this blood throughout the whole body.

Each side of the heart has valves that ensure blood flows in one direction – forward rather than backwards.

Frequently Asked Questions

What Causes Heart Disease?

The most common cause of heart disease in our pets is due to valve problems.  The left side valve wears out quicker in pets, probably because of the extra work this side of the heart has to do.  When the valve is damaged it results in some blood leaking backwards, the vet will usually hear this as a murmur.   A murmur can be heard in some pets from birth due to developmental heart problems, but more often it is seen as an aging change, as the valves wears out over time.   As the valvular damage progresses, the leak may become more severe and more blood will leak backwards and this will make the murmur sound louder.

What happens with Heart Disease?

The effect of the blood leaking backwards from the left side of the heart is that less blood will be pumped through the body and more blood will travel back into the lungs.   This results in fluid leaking into the air sacs, preventing oxygen from being absorbed.   Additionally, the left side of the heart will stretch as it fails to pump the blood in the forward direction.

What are the Common Signs of Heart Disease

Tiredness and lagging on walks due to organs and muscle not receiving sufficient blood flow
Coughing, panting, shortness of breath due to less oxygen absorption

From the time a murmur develops, to the time signs of heart failure present, can be a few months to several years.Less often the right side of the heart is affected.  This will result in poor blood flow through the lungs and resultantly less blood reaches the left side of the heart and hence the rest of the body.   Instead, blood will back log in the vessels of the abdomen rather than the lungs as occurs in left sided heart failure.   In these patients, coughing may not be the main sign but instead a swollen abdomen, due to fluid leaking from the vessels into the abdomen.Heart failure begins when the heart is not able to provide enough blood with adequate oxygen throughout the body. This causes the body’s cells to become desperate and that triggers a series of reflex responses to attempt to correct the problem.  These responses involve conserving fluid to increase blood flow and constricting blood vessels to improve blood pressure. Eventually these changes make the heart work harder (ie pushing a higher volume of blood through narrower tubes) and heart failure progresses.

How Is Heart Disease Diagnosed?

The first indication that heart disease is present relates to signs your pet may show.  These most commonly involve

tiredness
breathing problems and coughing
but can also include
decreased appetite
collapsing
weight loss and
a pot-bellied appearance.

Quite often when your vet listens to your pet’s heart, they will also hear changes such as

a murmur,
a change in heart rate or
an erratic heartbeat.

If heart failure is present then a change in breathing sounds may also be heard with a stethoscope.

A chest x-ray is one of the best ways the vet can see that the heart is not functioning properly.  It may show that the heart has enlarged to cope with the extra pressure and the lungs may show changes indicative of fluid leakage.  X-rays are not only a good way of diagnosing heart disease but are also helpful in determining the severity of it as well as improvements after starting medication.

If an erratic heart beat has been heard by the vet then an ECG maybe performed.

Heart ultrasound gives the best picture of the heart chamber sizes, heart muscle activity and the heart valves. Ultrasound can give us an idea of the cause of the heart disease as well as the best drugs for treatment.

What Is The Treatment For Heart Disease?

The aim of treatment is to minimise the pressure the heart has to work against and enhance the heart muscle function, so that it can pump more effectively.

This involves:

Adjusting exercise and diet.
Diuretics to reduce the fluid retention and leakage into lungs
Drugs that assist the heart muscle to work more efficiently
Drugs that relax and dilate blood vessels to make it easier for blood to flow forward
Enzyme inhibitors that block the body’s negative responses to heart disease such as fluid retention and blood vessel constriction
Anti-arrhythmic drugs may be started if an abnormal rhythm is diagnosed on ECG
In compromised patients, oxygen is often required

Elgar Road Veterinary

Contact Us

Heart disease can sneak up on all of us, so ensuring your pet has regular health checks may allow us to pick up problems before you are even aware there is anything going on.

If you would like any further information about heart disease or would like to organize a visit with our Elgar Road Vets please do not hesitate to call (03) 9899 9518, we would be happy to help.