The main reason diabetics are cautious when it comes to potatoes is their very high glycemic index (GI) value. The glycemic index is important for diabetics because it is a measure of the impact a particular food has on blood glucose levels once it has been digested.
The two most common causes of congestive heart failure in dogs are mitral valve insufficiency and dilated cardiomyopathy. In cats, hypertrophic cardiomyopathy is the most common heart disease. Genetic predisposition is clearly the most common underlying reason for the development of congestive heart failure.
Congestive heart failure can cause heavy dog breathing because it means your dog's cells aren't getting enough oxygen. His respiratory system tries to compensate for this by working overtime, leading to labored dog breath. If your dog is suffering from heart failure, he may breathe easier when sitting upright.