Heart Murmurs in Cats: What are they?
A heart murmur may be heard by your veterinary cardiologist when they listen to your cat’s heart. A heart murmur is caused by turbulent blood flow within the heart or the large vessels exiting from the heart. This results in an abnormal noise that can be heard by your vet when listening with a stethoscope.
Heart murmurs are assessed and graded according to certain criteria. Grades 1 - 6 are recognized, with Grade I being the mildest, and Grade 6 the most severe. The grading system is based largely on how loud the murmur is, but other factors are also considered, such as the area over which the murmur is audible.
- Grade 1 heart murmur in cats: Hardly audible.
- Grade 2 heart murmur in cats: Slightly audible.
- Grade 3 heart murmur in cats: Most common grade of heart murmur.
- Grade 4 heart murmur in cats: Louder, radiating murmur, often on both sides of the chest.
- Grade 5 heart murmur in cats: Has vibration and can be heard without the stethoscope touching.
- Grade 6 heart murmur in cats: Loudest murmur with vibration and can be heard without the stethoscope even touching.
The grade of the heart murmur does not necessarily relate to the degree of severity of the underlying heart problem. Some severe heart conditions may not be associated with any heart murmur at all, and some quite loud murmurs may occur with relatively small defects.
If you have a cat that is in need of surgery then all of this may lead you to wonder about a heart murmur in cats and anesthesia. Our vets are here to reassure you that having a heart murmur doesn't automatically mean that your cat is unable to receive anesthesia. This just means that your vet will need to dig deeper into the cause of the murmur first to determine how safe the anesthetic would be for your kitty.
Symptoms Of A Heart Murmur
The most common symptoms that are observed with a cat that has a clinically significant heart murmur are poor appetite, weight loss (or stunted growth in a kitten), breathing problems, pale gums, lethargy, or weakness.
Causes Of Heart Murmurs
One question that our vets have been asked is 'Can stress cause a heart murmur in cats?' and the answer is yes, stress can indirectly cause heart issues which lead to murmurs. The presence of a murmur generally implies an underlying heart condition along with various other causes.
In young kittens, ‘innocent’ heart murmurs may be heard as an incidental finding. These are usually no longer present when the kitten is older. Anemia is another cause of heart murmurs in cats, but the cats often show other signs of lethargy and anorexia as well.
Occasionally, older cats are reported to have incidental heart murmurs, which is when the blood flow within the large vessels exiting the heart may occasionally be heard as a murmur.
Heart Murmur in Cats Treatment
When a heart murmur is first discovered in a cat, an investigation will be performed to find out the underlying issue. This may involve further tests through the cardiology department such as an X-ray of the heart or a cardiac ultrasound examination.
If however the cat is showing no other signs of a problem and is exercising normally, then your vet may suggest you come back for a second examination in a few months to reassess the heart murmur and see if it has changed.
Sometimes if the cat is well and the heart murmur is unchanged, a periodic examination will be recommended.
The only way to determine if there is any disease within the heart itself that may be causing the murmur is to perform a detailed ultrasound examination of the heart. This is completely painless and is normally performed in a fully conscious cat.
You may also be concerned with the heart murmur in cats' life expectancy but you can be reassured that many cats with a heart murmur can live a long and healthy life. What is important is to have your cat's condition accurately diagnosed so that the symptoms can be managed allowing your cat to live comofrtably.
Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.