Hi Jennifer,

Thanks for your question.

There are a few questions here so I’ll answer them in two parts.

How serious are heart murmurs in cats?

First off, I’m sorry to hear that you are a little confused after an appointment with your veterinarian. When we hear a murmur in the heart we do have difficulty knowing whether there is severe heart disease or if the murmur is innocent. The higher the grade the murmur is, the more likely it is serious and could cause clinical problems including cardiac arrest.

How are heart murmurs graded?

The fact that he suggests this murmur is grade 3 or 4 makes it a more serious concern – murmurs are graded from 1 to 6. To evaluate heart murmurs in cats, the first test I would have performed is a cardiac ultrasound. It’s true that cardiologists will perform this test but there are ultrasonographers who travel around to clinics who do it as well. There are quite a few of them and it’s likely that your veterinarian may know of one and could give them a call and book an appointment at your current clinic so that you don’t have to go elsewhere. The ultrasound is a very thorough test and it should be able to pinpoint the source of the murmur, the type of heart disease, whether treatment is necessary, and the course of treatment as well as indicate the severity of the condition.

I would also recommend that you perform routine blood work to make sure that there are no other underlying conditions. There are many reasons for seizures and if what your cat experienced truly was a seizure and it occurs again, I would recommend you start performing a work-up with your veterinarian to determine the cause of the seizures.

All the best.

Dr. Clayton Greenway