Heart Murmurs in Cats
A heart murmur is caused by turbulent blood flow within the heart or the large vessels exiting the heart. This results in an abnormal noise which your vet will hear when he listens to your cat’s heart during an examination. Many cats that have a heart murmur do not experience any problems but it is important that any heart murmur is investigated and assessed by your vet .
Heart murmurs are assessed and graded from 1 to 6 (1 being the most mild and 6 the most severe) according to certain criteria. The grading system is based largely on how loud the murmur is compared to the other normal heart sounds but other factors are also considered, such as the area over which the murmur is audible.
Although many heart conditions are associated with heart murmurs, some severe heart conditions in cats are not associated with a heart murmur and there are also various other conditions that can cause a heart murmur.
In young kittens, heart murmurs may be heard at first examination but may well not be present at examination 6 months later. Anaemia is another cause of heart murmurs in cats but the cats often show other signs of lethargy and anorexia as well.
When a heart murmur is first detected in a cat, your vet will look for any other clinical signs that would alert your vet to other clinical problems (ie, lethargy, abnormal respiratory pattern/rate/effort, pale gums). These will be assessed and investigated to establish the underlying problem.
If your cat is very well at home, shows no other clinical signs of a problem and exercises normally, then your vet will recommend a repeat examination in 3-6 months time to reassess the heart murmur and see if it has changed in any way or if the cat has developed any other clinical signs.
Another abnormality that may occasionally be heard is a 'gallop' sound which signifies an abnormality in the function of the heart. This may either be a sign of a serious heart problem or an alteration in the speed of blood flow through the heart. As gallop sounds represent potentially serious conditions, further investigation will be highly recommended.