Signs of heart disease are usually easier to see in dogs and less detectable in cats. Schedule an appointment with your veterinarian especially if they fainted, have a persistent cough, difficulty breathing, or noticeable abdominal swelling. 

The heart is a pump

Think of your pet’s heart as a pump that circulates blood to the lungs and throughout the body. Heart disease progresses slowly over time, and as it does it prevents the pump from being able to do its job properly. The heart (pump) is still doing its best, but its performance is less than ideal now that it’s being blocked up. This decreased performance causes congestion or a pressure buildup.

Now we hit a traffic jam When the heart is experiencing congestion, it’s like a traffic jam. The blood—traffic—cannot move forward as it usually does, so it builds up behind the problem area. This congestion (pressure) builds up in the lungs if the left heart is failing, and in the body if the right heart is failing.

Let’s talk leaks

When the pressure builds up high enough, fluid will leak out. Fluid leaks into the lungs with left heart failure and into the abdomen with right heart failure. In the lungs, this fluid fills the tiny sacs where normally only air should be. This fluid makes exchanging oxygen more difficult. The pet has to take more breaths to absorb the same amount of oxygen. This increases the breathing rate and effort, sometimes causing a cough.

Watch for signs

The clinical signs of congestive heart failure in dogs and cats are an increase in breathing, a cough or increase in a cough (this one is for dogs only—in cats, coughing is mostly associated with lung disease), excessive panting or wheezing, restlessness, decreased appetite, lethargy, weakness, collapse or fainting. If you see any of these problems, don’t hesitate to reach out to your veterinarian and make time to get your fur baby looked at.



1. Cardiac Care for Pets

2. Megan King, VMD, DACVIM (Cardiology)

3. (Infographic) – CVCA