Symptoms of Canine Heart Disease

According to the American Veterinary Medical Association, 3.2 million dogs in America will develop canine heart disease each year. It is the leading cause of death in dogs, affecting more than 60% of older dogs, and more than 10% of all dogs. Though is it more common for a dog to develop heart disease later in life, no breed, size, gender or age is immune. Heart disease can potentially cause canine heart failure.


Depending upon which side of the heart is affected, symptoms can include fainting, tiring easily, unwillingness or inability to exercise, fatigue, depression, rapid breathing with difficulty and/or coughing. If he is experiencing right-side congestive heart failure, the preceding symptoms will be coupled with swollen abdomen and limbs. Having a canine heart murmur will not necessarily lead to canine heart disease unless it is accompanied by symptoms other than those associated with heart murmurs. Symptoms range from dog to dog, and every dog may not exhibit every symptom.

Canine heart disease is a serious problem affecting the heart muscle. When heart disease occurs, certain parts of the heart cease to function properly, forcing the rest of the heart to have to compensate. Heart disease can be a slow, gradual condition. It starts with the dog having a lack of energy or willingness to exercise. Lethargy, increased panting and puffing, general fatigue and an increase in daytime sleeping will also signal the possible onset of heart disease. Coughing during the night or first thing in the morning, along with loss of appetite and weight loss, are also warning signs. Sometimes a dog will develop a potbellied appearance or a gray or bluish tinge to their gums. This is due to accumulation of fluid in the abdomen and not enough blood circulation.


Heart disease can be caused by a birth defect, arrhythmia (irregular heart rhythm), cardiomyopathy, injury, age, infection or heartworms. Some breeds develop heart disease due to genetic defects. This accounts for only 5% of the incidence of heart disease in dogs. These breeds include cocker spaniels, poodles, chihuahuas, schnauzers, Lhasa Apsos and Yorkshire terriers. Other acquired causes include heart valve malfunction, weakening of the heart muscle or an enlarged heart. This leads to disruption in blood circulation, which can affect the entire body. Heart disease gets progressively worse over time and is magnified by obesity.


A veterinarian will use blood tests (to check for heartworms), chest x-rays, electrocardiograms, ultrasound and echocardiograms to determine if heart disease is present. Early detection can allow a dog to live a longer, healthy life.


Treatment can include surgery if the disease is caused by defective heart valves. Otherwise medications are used to reduce fluid retention in the lungs and abdomen, increase the volume of blood pumped per heartbeat and normalize the heart rhythm. After a period of rest, resumption of regular exercise and proper diet, including vitamins, minerals and less salt in the diet, will help maintain the quality of the dog's life. Yearly checkups by a veterinarian will ensure that heart disease is being properly monitored.