A heart problem can affect your pet at any age although it is more often found in older pets. Heart disease affects 10% of all dogs, 24% of dogs over the age of 7 and 33% of small breed dogs over the age of 10 years. Heart failure occurs when the heart no longer has the ability to pump blood around the body effectively. Heart failure can lead to congestive heart failure. If an animal is suffering from congestive heart failure, it usually accumulates fluid in the lungs although it can result in fluid accumulation in the abdomen as well. Animals suffering from congestive heart failure often experience difficulty breathing and frequent coughing. Some causes of heart failure include: congenital heart disease (animals born with a heart problem), valvular heart disease (abnormalities of the valves of the heart), dilated cardiomyopathy, heartworm disease, and arrythmias (rhythm disturbances).
Dr Fiona Kilpatrick Puppy Health Check
Many heart problems can be identified on physical examination by ascultating the heart. Additional tests are usually required to accurately identify the cause of the heart disease. Additional tests include EKGs (electrocardiograms), radiographs (X-rays), and ultrasounds. 
Heart disease is a serious life threatening condition but early diagnosis and appropriate therapy can extend your pet’s life. The treatment of heart failure involves a combination of medications to optimize the quality of life and extend the life of your pet. For more detailed information and help in understanding heart failure go to Vetmedin.
This website has lots of great information, tools and apps you can use to manage Your Dog’s Heart
