When you think about your pet’s health do you ever think about their heart? Heart problems are actually
relatively common in older pets, especially dogs. For humans we worry about coronary artery disease and
atherosclerosis, the most common causes of heart attacks. Pets are different! They do not develop the same
type of heart disease as humans. The two most common types of heart disease we veterinarians see are
valvular disease and dilated cardiomyopathy, also known as DCM.


DCM has been in the news a lot lately in relation to concern about the connection between grain-free diets
and an increased number of DCM cases. Dilated cardiomyopathy means that the heart muscle itself becomes
thin and weak, leading to poor ability of the heart to pump effectively. Certain breeds are predisposed to
developing DCM including Dobermans, Great Danes, Cocker Spaniels and Boxers. Dietary deficiencies in
certain nutrients such as carnitine and taurine have been linked to the development of DCM. Symptoms of
DCM can include lethargy, weakness, weight loss, cough, and increased respiratory effort. If you have an at-risk breed or your pet is exhibiting any of these symptoms, it is important to have them checked by a
veterinarian. Early intervention with appropriate medication can help improve the quality of life and prolong
the lifespan of pets suffering from DCM.


Valvular disease or endocardiosis is another frequent cause of heart disease, particularly in older pets and
Cavalier King Charles Spaniels. As pets age, the valves in the heart can become thickened and deformed. The
mitral valve, the biggest valve in the heart, located in the left ventricle, is especially vulnerable. If the valve is
unable to close tightly as it is designed to do, leakage of blood can occur between the heart chambers. This
causes a characteristic sound called a murmur. A veterinarian can auscult this sound and make a
recommendation for what steps to take to further assess its cause.


Frequently diagnostic tests are needed to assess heart disease in our pets. Chest x-rays and
electrocardiograms are a good place to start. Chest x-rays allow the veterinarian to look at the size of the
heart, and to evaluate the lungs for signs of heart failure. An echocardiogram or ultrasound of the heart is
recommended if the heart is enlarged on x-rays. An echocardiogram gives a more sensitive picture of the
heart than an x-ray can. Sometimes a visit to a veterinary cardiologist will be recommended by your general
practice veterinarian. These specialists have received advanced training in heart related problems and are
the ones best equipped to handle patients with more severe heart disease.


There are several medications that are available to help treat heart disease in pets. Pimobendan or Vetmedin
is a positive inotrope which means that it helps the heart muscle contract. It can be useful in cases of both
endocardiosis and DCM. ACE inhibitors like enalapril cause dilation of blood vessels so more blood volume is
available to the heart. Diuretics are a mainstay of treatment for pets that have advanced heart disease and
are suffering from congestive heart failure. Diuretics increase fluid loss through urination, helping to keep
fluid from building up in the lungs as the result of a weakened heart.


To recap, signs of heart disease to watch for in pets are lethargy, exercise intolerance, persistent cough,
increased respiratory rate or effort, collapse and weakness. If your pet is suffering from heart disease
diagnostic tests may include x-rays, echocardiogram, and electrocardiogram. There are many medications
that can help support the heart and prolong both your pet’s lifespan and quality of life. Consider avoiding
grain-free diets unless specifically directed by your veterinarian