While X-rays are excellent for aiding in diagnosis as they give us an idea of the general shape and size of the heart, an echocardiogram lets us look into the heart to see how the valves and chambers are structured. It can reveal changes that might not be picked up on an X-ray, so it's a very valuable tool for diagnosis.

A murmur is a sound we hear when we're listening to the chest. Typically, we'll find a murmur if we come in for exercise intolerance or a cough, and we listen to the heart and hear that extra sound between the beats. Or, we might pick up a murmur during a regular physical exam. Murmurs are graded from one to six, with one being the quietest and six the loudest.

The first sign of a heart issue in a dog varies. In some cases, a dog that used to be able to run three miles a day may now barely make it down the block. Another sign could be a persistent cough that lasts for several months, which doesn't seem to be going away, even though the dog doesn't appear ill in any other way.

Heart failure in dogs is when we're starting to notice not only the signs of cardiac disease but a decompensation, where they're no longer able to cope with it. Typically, we see that as a response to increased fluid retention somewhere, whether that's in the lungs, causing difficulty breathing, or we start to see fluid filling the belly. In the abdomen, starting to get free fluid in the abdomen is a really good sign that we've got some heart problems on the right side. In both cases, those are very severe and need to be seen by a veterinarian as soon as possible.

That depends on the cause. In hypertrophic cardiomyopathies, we're trying to make sure that we're getting medications on board that increase the ability of the heart to pump and decrease the resistance the heart has to work against. In dilated cardiomyopathy, where we're seeing that taurine-deficient cause, we're recommending a diet change to supplement that taurine.

An enlarged heart is what we would call any sort of dilated or hypertrophic cardiomyopathy where either the heart is enlarging and thinning in dilated cardiomyopathy, think like filling a water balloon, it gets stretched and thinner, versus hypertrophic cardiomyopathy where the heart is actually laying down extra muscle, and that's usually in response to increased resistance or increased regurgitation through one of those one-way valves.

It absolutely can. So in the 70s and 80s, we were noticing an increase in dilated cardiomyopathy in dogs that typically was a result of a lack of taurine in their diet, and we've actually seen a resurgence of that disease in the past 10 to 20 years as grain-free diets have become more popular. A lot of the grain-free diets don't add in that taurine. It's an amino acid that is very common in grains, and if we're using a grain-free diet, we're not getting those grains. We need to replenish that taurine somehow.

Cardiomyopathy is a blanket term for a problem in the muscle of the heart, so cardiomyopathy is a problem in the heart muscle, and that can arise from a number of causes.

A heart murmur is really just a sound. It's an abnormal sound between the first and second, the lub-dub of the heart. Typically, it sounds like rushing water, various volumes, so we'll describe it as a grade one to six, grade one being very quiet, grade six being fairly loud.