The first symptom of a bad heart condition in dogs is exercise intolerance. A healthy dog ​​may be able to walk for an hour without any problems, but a dog with heart disease may pant and have tachycardia after walking a few steps. , and may even cause instant shock or death. This is a sign that your dog's heart is not providing enough oxygen and energy to the body efficiently.

If the dog's heart failure is severe, it may cause symptoms such as heavy breathing and cyanosis of the mucous membranes. This is due to insufficient blood supply to the heart, resulting in lack of oxygen. The dog may show symptoms such as reluctance to move, panting when moving, and rapid heartbeat.