The echocardiogram is an ultrasound of the heart. An x-ray is a two-dimensional view or picture of the heart or of the chest. In contrast, the echocardiogram is a more specialized view of the heart; it can detect the heart's motion and look at chamber sizes and blood flow through the heart.

The primary way we hear them is with our stethoscope, and then we can do a test with an echocardiogram to figure out why that murmur is present.

Some of those symptoms may be that your pet has shortness of breath, or they may have a progressive cough. Sometimes they'll even just collapse, or they'll be weak when they're exercising.

If your dog's been on consistent heartworm prevention and you miss a single dose, the risks are going to be pretty low. We just need to get started back on heartworm prevention as quickly as possible. The best thing to do in that situation, because it does kind of depend on the specific circumstances, would be to contact your veterinarian and get their advice as to whether there should be an additional heartworm test. At least find out when the next heartworm test should be, depending on how long there was a lapse. But if you miss a few days here and there, it's not likely to be a big deal, but it is still crucial to try to stay on time as much as possible.