The heart is a muscle. We all learn this in elementary school. Good thing for us and our animals, the heart beats whether we want it to or not. We don’t have to think about making it beat, and it speeds up and slows down right when it needs to. Again, this is obviously a good thing. However, when the electrical impulses of the heart are short circuiting or when the pump mechanism of the heart gets leaky and efficient, problems occur.
Think of the circulatory system as the Perimeter around Atlanta. Cars are the red blood cells, police and ambulance are the white blood cells. Lets just say that cars can only go around the Perimeter once on a single tank of gas, and there is one gas station right at the top of the Perimeter. If the gas station is quick, cars shoot around the circle in a nice, even flow. But if the station has employees that start to send cars the wrong direction or if the gas station looses a pump, then a traffic jam results. Cars back up and more slowdowns occur. The offramps get crowded and side streets start to back up. I’m sure you can picture the disaster that would ensue, or if you’ve lived in Atlanta long you have been a part of a disaster at least this bad.
So the heart gets less efficient, and blood starts to back up. The liver gets bigger because blood backs up into it, and fluid starts to settle in and around the lungs because there is nowhere else for it to go (orange and red). The heart gets bigger in an attempt to pump more blood and become more efficient and this pushes the trachea up into the top of the chest cavity (blue).
What does all this mean for the patient? It means that the abdomen, chest, or both cavities will start to fill up with fluid because the heart can’t keep it up. If the lungs fill with fluid, you will see a cough that is often flecked with blood. Animals in heart failure often breathe faster than usual, and can’t seem to get comfortable.
How do we fix heart failure? We need to get less cars and more gas pumps. The main therapy for heart failure is getting excess fluid out of the body. If we can reduce the amount of “stuff” the heart has to pump, then it won’t get backed up as quickly. Increasing its ability to contract and pump more blood around also helps the process. If there are electrical disturbances making the heart inefficient, sometimes these can be corrected by medications as well.
Unfortunately, heart failure is common in many small breed dogs. Fortunately, the prognosis is good for us to be able to control this animal for a reasonable length of time on medications.
As an FYI: Dogs or cats do not have heart attacks.
– Doc Cleland