“I’m hearing a heart murmur” is not something you ever expect to hear from us during a “routine” wellness exam for your cat. However, some studies report the incidence of heart murmurs in cats up to 50%. This can be scary to hear, but the majority of these cats with murmurs never develop heart disease. In fact, sometimes stress alone can cause a murmur. In this case if we allow the cat to acclimate to the exam room longer or recheck the heart in the comfort of their own home, the murmur doesn’t exist anymore. Sometimes with or without a cat’s favorite cat-friend, person, or special blanket can make the difference of a murmur in the clinic, or not, if it’s stress-induced. Even with subtle murmurs, many cats live long full lives, undergo anesthetic procedures well, tolerate medications, and never ever have problems.
However, it’s our role as advocates for your cat’s health to educate you on the incidence of heart disease and what you can do to detect it early and know your options. According to the American Veterinary Medical Association (AVMA), heart disease affects 1 of every 10 cats worldwide. If left undetected and untreated, it can lead to congestive heart failure in cats. In one study of 103 privately owned cats that appeared healthy, 16 of them had a serious feline heart condition called cardiomyopathy (with no apparent signs).
Diagnosing heart disease is not always easy in cats. “Silent” heart disease is common.
Once your cat develops signs of heart disease, it is often very far advanced in disease and carries a worse prognosis. Subtle signs may be lethargy and unwilling to play, but more common are alarming signs like inability to walk or breathe, or collapsing or fainting in which case medical attention is urgent. Sadly, in many cases, heart disease is silent for years due to the elusive nature of cats. In some cases, sudden death is the first and only sign of heart disease.
As your cat’s health advocates, we have two goals when we examining them:
- Identify issues that may be causing discomfort, illness, or may warrant additional investigating.
- Educate you as your cat’s caretaker. We want you to know all the health concern findings and understand all the options moving forward.
When a heart murmur is heard, we want to help you make an educated decision on how you would like to proceed with your cat’s care. We respect that many people chose a “watch and wait” approach, however as feline specialists, we are here to be a voice for your cat, and to make sure you understand your choices.
Scoring your cat’s heart murmur
When we listen to your cat’s heart, we’re not only counting the heart rate but also listening to the loudness, the pitch, the rhythm, and for any abnormalities in the “beat”.
Hearing a murmur tells us there is a disorder of the heart or associated blood vessels. Typically blood flows in one direction through the 4 main valves in the heart. If there is abnormal flow or regurgitation of the blood flow, we hear a “whooshing”, called a murmur. If heard, we always grade a murmur on a scale of 1-6, so we have something objective to track over time. Grade 1 is barely audible, while Grade 6 is very easy to hear and we may even be able to feel the murmur with our hand outside the chest. Some murmurs worsen over time to a higher grade, some do not.
Identifying the Cause
From there, we need additional diagnostics to determine if your cat has a primary heart disorder such as enlargement of the heart chamber muscles (hypertrophic cardiomyopathy), degeneration of the valves, endocartitis (infection or inflammation of the valves), heartworm disease, or others.
Your cat may have a disease or problem not directly associated with the heart (hyperthyroidism, high blood pressure, extreme stress, or anemia). This is important to rule out first with basic labwork and blood pressure measurement.
What can you do if you’re concerned about heart disease in your cat?
An individualized pro-active approach to heart disease is best. Routine thorough physical exams are the first step in being an advocate for your cats’ health. Frequent exams as your kitten develops during the first year in life, then semi-annual exams are recommended.
Being pro-active is key in certain breeds with higher rates of heart disease and in senior cats. Maine Coons, Persians, Siamese, Ragdolls, Sphynx, American Shorthair, and long-haired cats in general should be screened early in life even without a murmur or symptoms. Due to mixed genetics of cats, however, any “regular” cat or Domestic Shorthair has a risk of silent heart disease.
If a cat has a murmur, an echocardiogram is recommended and considered the gold standard. However, there are other options based on the individual cat and owner preference. An echocardiogram is non-invasive and tells us the most, but there are other tests outlined below that do give us good information prior to this step:
- A blood test – Cardiopet proBNP is similar to those used to detect heart disease in humans. This can easily be added on to your cat’s routine wellness screening labwork. BNP is the acronym for “brain natriuretic peptide,” a protein originally isolated from the brains of pigs. We now understand the primary source of BNP is not the brain, but rather the ventricles of the heart, and the main signal for the release of the peptide is excessive stretching of the heart muscle. When the heart muscle cells (myocytes) are stretched and/or stressed, this biomarker is in excess in the blood stream. This is a simple, relatively inexpensive, way to screen cats for heart disease. If this number is low, we can rest assured that your cat does not have heart disease, but needs to be continually monitored in the future. If the number is high, then we will discuss options for further investigation for the cause of heart stress/disease.
- A blood pressure test – A routine test for patients at Cat Care Clinic, done with all Senior Cat Profiles every 6 months.
- Radiographs can be taken to check for abnormalities in the heart or lungs.
- An electrocardiogram (ECG) evaluates the electrical activity of the heart
- An echocardiogram – An ultrasound to measure the heart structure and function. We have the benefit of teaming with a Board Certified specialist at Cat Care Clinic to provide echocardiograms for our patients in the comfort of our feline-friendly clinic. Patients are fully awake and do very well for this non-invasive look at the heart. An echocardiogram will provide what we need to know about the inside of the heart and its full functionality.
Each cat and case is different. We take the whole picture into account when determining the best diagnostic and treatment plan that works for you and your cat. Medications such as beta-blockers, diltiazem, or diuretics and ACE inhibitors may be prescribed depending on echocardiogram findings and your cat’s overall health. Many cats can live for many years with stabilized heart disease.
Our goal at Cat Care Clinic is always to provide the best and most comprehensive medical care possible for your cat and the best education for you, all in our clinic built to reduce stress and fear for your beloved feline friend.
Please call or email us for more information or questions about your cat and heart disease.