Canine Heart Disease: Symptoms, Causes, Treatment and Prevention

Canine Heart Disease
Symptoms, Causes, Treatment and Prevention

“There is no cure for most of the common causes of heart failure in dogs but,
with treatment, many dogs may live for years after being diagnosed.”

There are two basic forms of heart disease in dogs: acquired and congenital. Acquired heart disease is usually either atrioventricular valvular insufficiency (AVVI) (also known as endocardiosis), or dilated cardiomyopathy (DCM).

Overview/Snapshot of Disease or Condition

It’s estimated that about 11 percent of all dogs have canine heart disease. This figure rises to more than 60 percent in older dogs which means that heart disease in dogs is a frequent cause of death in our pets.

Canine heart disease can either be acquired or congenital. Acquired heart disease makes up 95 percent of all heart problems.

Canine Heart Disease – Symptoms

Congenital heart disease manifests as heart defects that a dog is born with and these problems are usually diagnosed when the dog is still a puppy. Congenital heart disease accounts for only about five percent of heart disease.

Atrioventricular Valvular Insufficiency (AVVI) is the most common form of heart disease in dogs. It usually occurs in small or medium-sized dogs. Some of the breeds most prone to AVVI include Cavalier King Charles Spaniels, Miniature and Toy Poodles, Schnauzers, Lhasa Apsos, Chihuahuas, Yorkshire Terriers and Fox Terriers. Male dogs seem to be affected more often than female dogs. Untreated, the disease will lead to congestive heart failure.

Canine Heart DiseaseDilated cardiomyopathy (DCM) is a disease of the heart muscle where the muscle is unable to pump with much effectiveness. The heart’s muscle contractions are weak so it’s not able to pump blood through the body’s vascular system as it’s supposed to. The heart becomes enlarged as it tries to pump harder, which only makes it less effective.

This disease, the second most common form of heart disease in dogs, will also lead to congestive heart failure if it’s untreated. DCM most often occurs in medium and large breed dogs such as Doberman Pinschers, Boxer dogs, Great Danes, English Springer Spaniels, German Shepherd Dogs, Dalmatians, Irish Wolfhounds, Old English Sheepdogs, Saint Bernards, Bulldogs and Cocker Spaniels. Most dogs are affected between the ages of 2 and 5 years old. Once again, more males than females are affected.

Here are some of the symptoms of congestive heart failure in dogs:

  • Fatigue and weakness
  • Decreased ability to exercise
  • Shortness of breath (due to build up of fluid in the chest)
  • Increased respiration
  • Coughing
  • Weak or irregular pulse
  • Rapid or irregular heart beats
  • Distended abdomen (due to fluid build up in the abdomen)


Canine heart disease can be caused by a number of dog health problems, including the following:

  • Normal wear and tear on the heart muscles and valves
  • Mitral valve prolapse
  • Damaged heart muscles
  • Infections affecting the heart muscles or circulatory system (endocarditis)
  • Canine Hypothyroidism
  • Congenital heart defects
  • Degenerative changes in the heart muscles or valves

Treatment for Canine Heart Disease

Treatment for heart disease in dogs will depend on the exact problem affecting your dog, his age, his overall condition and health, and how far advanced the problem may be. There is no cure for most of the common causes of heart failure in dogs but, with treatment, many dogs may live for years after being diagnosed.

Treatment for this canine health problem may involve diuretics to remove a build up of fluid in your dog’s lungs or abdomen. Furosemide is often used for this purpose. ACE-inhibitors may be used to open up your dog’s blood vessels and allow blood to flow more easily for his heart to pump. Inodilators may be prescribed to encourage the heart to contract more and to open up blood vessels. This will reduce the work that your dog’s heart has to do. The drug Vetmedin was introduced in 2007 for this purpose.

Your vet will need to monitor your dog and his medications to see that they are working as they should be. Let your veterinarian know if there are any changes in your dog’s condition or behavior, especially if a new drug is introduced.

Many dogs may have canine heart disease for years without showing any symptoms. A slight heart murmur may be the first sign, so check-ups are very important. However, once your dog has heart disease it will progress, so it’s important to begin treatment as soon as the disease is recognized.


There are a number of things you can do to prevent acquired heart disease in dogs.

  • Brush your dog’s teeth regularly. Clean teeth will prevent bacteria and decay from entering your dog’s bloodstream which can affect the heart. Brush your dog’s teeth at least once a week.
  • Watch your dog’s weight. Overweight dogs put more strain on their hearts.
  • Encourage your dog to exercise. Good fitness leads to a healthier heart muscle.
  • Feed your dog a good quality food. Make sure he’s getting good sources of protein, vitamins, minerals, Omega-3 fatty acids, and other ingredients in the food you feed. L-Carnitine and Taurine, in particular, are good for your dog’s heart health.
  • Your dog needs a vet exam once a year when he’s young. As he ages (over six years old), he may need to see the vet more often to make sure he’s staying healthy and fit.
  • Give your dog heartworm preventive. Heartworms kill and will stop the heart.
  • Watch for the signs of canine heart disease and take them seriously. See your veterinarian if you notice your dog acting lethargic, coughing or having trouble breathing.

Heart disease, along with so many other canine health problems, may be congenital and without a permanent cure. However, with proper care and regular veterinarian check-ups, the odds that your dog will lead a healthy, happy life go up dramatically.

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