Canine Cardiology

Regular veterinary checkups are a key component in keeping your dog’s heart healthy. The best thing you can do as a dog owner is to make sure your dog has thorough medical checkups at least once a year. During this examination the veterinarian will carefully listen to your dog's heart. Examination with a stethoscope is the most cost-effective approach to diagnosis of heart disease in dogs.

Canine cardiology is the medical field that diagnoses and treats a dog's cardiovascular system, which includes the heart and blood vessels. The veterinarians at Metropolitan Veterinary Center can diagnose and help develop a treatment protocol for canines that suffer from:

  • Congestive heart failure
  • Heart disease
  • Hypertension
  • Dilated and hypertrophic cardiomyopathy
  • Valvular Disorders

Here are the basics of how a dog's heart works:

  • Veins carry exhausted blood from the body to the right atrium
  • Blood is stored in the right atrium momentarily until being pumped into the right ventricle
  • The right ventricle pumps the blood into the lungs, where it is infused with fresh oxygen
  • The blood then flows from the lungs back into the heart via the left ventricle
  • The largest muscle of the heart, which is located in the left ventricle, pumps the freshly oxygenated blood to all other organs and body parts
  • Once the blood is circulated and exhausted, veins carry it back toward the heart via the right atrium to begin the process again

Heart Disease In Dogs

According to the American Veterinary Medical Association (AVMA), heart disease in dogs affects 1 of every 10 dogs worldwide. Dog heart disease is a condition in which an abnormality of the heart is present. Heart disease in dogs can lead to heart failure if untreated.

Heart disease in dogs can be either congenital or acquired:

  • Congenital heart disease in dogs is present at birth, and can be inherited from the parents
  • Acquired heart disease in dogs often occurs in middle-aged to older animals due to wear and tear on the heart structures, but can also result from an injury or infection

There are several common causes of congenital dog heart disease, including:

  • Patent ductus arteriosus (PDA): The most commonly diagnosed of all the heart problems in dogs, and happens when the vessel connecting the aorta and pulmonary artery in the developing fetus (known as the ductus arteriosus) does not close properly shortly after birth
  • Aortic stenosis (or subaortic stenosis): Most commonly seen in large breed dogs, and results in a narrowing or partial blockage of the aorta as it leaves the left ventricle of the heart. The aorta is responsible for transporting blood to the rest of the body
  • Pulmonic stenosis: A narrowing of the valve that allows blood to flow from the heart to the lungs, it is the third most common congenital heart defect seen in dogs
  • Ventricular septal defects: This results from the presence of a hole between the heart's right and the left ventricles
  • A persistent right aortic arch: This results from a fetal structure (known as an aortic arch) that does not deteriorate as it should, but instead it encircles a dog's esophagus and causes abnormalities in the esophagus' growth and function

Some common causes of acquired dog heart disease include:

  • Valvular disease affects all dog breeds, but is especially common in toy and small dog breeds. The most commonly affected valve is the mitral valve, but other heart valves can also be affected
  • Myocardial disease also called cardiomyopathy, affects the heart's muscle structure. Cardiomyopathy affects all dog breeds, but is most commonly diagnosed in large dogs
  • Cardiac arrhythmias are abnormal heart beats or heart rhythms resulting from dog heart disease that affects the heart's (electric) regulatory system and thus, the ability for the heart to beat properly
  • Pericardial disease affects the pericardium, or the sac that surrounds the heart, by restricting the heart so it is unable to beat properly

Additionally, acquired dog heart disease can come from infections and viruses like heartworm or parvovirus. Because many of these types of heart disease share symptoms and characteristics with each other, proper diagnoses require consultation with a dog cardiologist.

Congestive Heart Failure In Dogs

Congestive heart failure in dogs occurs when the heart is no longer able to support the circulatory system. Although geriatric or sedentary dogs may show no apparent symptoms of congestive heart failure until its advanced stages, habitually active adult dogs usually show some common signs of distress. A few prevalent symptoms of congestive heart failure in dogs include:

  • Coughing
  • Edema
  • Rapid breathing

There are various stages of congestive heart failure in dogs that veterinarians use to determine severity:

  • Asymptomatic: Dog heart disease is detected, but there is a lack of any outward signs. Additionally, a cardiac murmur or arrhythmia may also be present
  • Mild to moderate heart failure: Significant clinical signs of congestive heart failure are in evidence both at rest and while active
  • Advanced heart failure: Critical clinical signs are evident, including respiratory distress, ascites (fluid in the body cavity), and profound exercise intolerance.The prognosis will worsen with each passing stage, and the need for aggressive treatment will increase

Symptoms Of Heart Problems In Dogs

There are several possible symptoms of heart problems in dogs that dog owners can be on the lookout for, including:

  • Lethargy/weakness/exercise intolerance
  • Difficulty with or discontinuing exercise
  • Shortness of breath or difficulty breathing possibly accompanied by fluid buildup
  • Fast breathing during dormancy (not panting)
  • Fainting/collapse
  • Chronic coughing
  • Regularly elevated heart rate

Because these symptoms of heart problems in dogs can indicate one of many possible conditions, and potentially even something unrelated to the cardiovascular system, we recommend scheduling an appointment with your veterinarian immediately if you suspect anything out of the ordinary.

Early Detection Is The Key To Treating Heart Disease In Dogs

Early detection of dog heart disease requires due diligence on the part of dog owners. After all, a dog cannot articulate to human beings how it feels in a language we can understand. One of the most effective diagnostic tools for detecting dog heart disease is a cardiac examination. A dog cardiologist can employ some or all of the following procedures during a cardiac examination:

  • Physical exam: We listen to your dog's heart and lungs with a stethoscope to check for abnormal sounds
  • Blood pressure: We perform a standard, non-invasive blood pressure test to monitor systolic and diastolic pressure
  • Electrocardiogram (EKG): We measure the electrical activity of your dog's heart to diagnose heart arrhythmias among other conditions
  • X-Rays: With diagnostic imaging such as x-rays, we can view the heart's overall size, its positioning in the chest, and the general condition of the lungs
  • Blood analysis: We can perform a complete blood work chemistry to detect chemical deficiencies or surpluses that indicate cardiovascular issues
  • Ultrasound: We can view and measure your dog's heart's chamber, valves and muscles, as well as the major cardiac vessels using soundwaves and without any pain or invasion

Heart Medicine For Dogs

Many of the same heart medicines that medical professionals employ to treat human heart patients are currently available in veterinary medicine as well. These includes various types of heart medicine that has been proven effective for dogs. Choosing the correct medication and dosage will depend upon the diagnosis and stage of the heart disease. Follow up visits and progress checks are extremely important to determine the efficacy and response to treatment. This information will greatly aid our doctors in helping to insure that your dog has the best outcome for the longest time possible. We will work with you to give them the best quality of life possible.

Have Your Dog's Heart Examined At Your Next Veterinary Visit!