Stage 3 Heart Failure In Dogs. As your dog progresses through the canine congestive heart failure stages, you'll notice an increase in lethargy, swelling, coughing, and breathing problems. It is estimated that 10% of all dogs seen in primary care veterinary practices have heart disease.
The development of heart failure represents a specific measurable point in the development of heart disease. Congestive heart failure in dogs. Essentially, the blood is causing the pup to drown in his own fluids, which can be agonizing.