Ageing dogs commonly suffer from heart disorders. However, canine heart problems arise more from weak heart muscle, heart enlargement, inadequate valve function or arrhythmias, as dogs do not develop atherosclerosis (the build-up of fatty deposits on artery walls) as humans do. Please consult your veterinarian if your dog exhibits any of the signs of a heart attack. With proper treatment, your dog can continue to live a full and happy life.
Your dog may display a general weakness and fatigue, particularly following exercise, as his heart works to keep the blood flowing during periods of exertion. Some dogs with weakened hearts will even faint following physical activity.
Poor blood circulation and reduced oxygen in the blood will cause your dog's tongue and gums to develop a bluish discolouration. A weakened heart loses its ability to oxygenate blood as it struggles to maintain circulation.
When your dog's heart loses its ability to adequately pump blood throughout his body, the kidneys react by retaining salt and water to increase blood volume and to restore cardiac function to normal. Blood backs up as your dog's weakened heart struggles to handle the increased volume; fluids then leak into the lungs and body tissues causing oedema (swelling). This occurs more often in right-sided heart failure. In these cases, blood returning to the heart from the rest of the body backs up and causes fluid build-up in the abdomen, liver and limbs.
Breathing difficulties and a persistent dry cough occur when fluid builds up in your dog's lungs. These symptoms present themselves more frequently in cases of left-sided heart failure. This form of heart failure causes a backup in blood returning from the lungs to the heart.
Poor blood circulation to the digestive system and the liver can cause problems with appetite, vomiting, diarrhoea and constipation.