Heart Diseases

Regular veterinary checkups are a key component in keeping your pets’ heart healthy. Heart disease doesn’t discriminate, all pets are at potential risk. In some cases, the signs are obvious to the trained eye. In others, a serious heart disorder can remain hidden for years before finally expressing itself in a sudden, perhaps fatal, deterioration of function.

Heart Murmur

A heart murmur described abnormal blood flow during the beating of the heart. Heart murmur are graded on a scale of 1 (soft) to 6 (very loud with a palpable thrill on exam). A heart murmur is a physical exam finding that usually warrants further testing such as an echocardiogram (ultrasound of the heart).

Congenital Defects Dog/Cat

Most heart disorders are acquired during the course of an animal’s life, but others are present at birth. Congenital heart disorders are relatively rare, occurring only in an estimated one or two percent of kittens and puppies. The most common congenital disorders are heart valve malformations and holes in the septa. Abnormal valve development and structural problems can occur, the end result is typically a valve that cannot close properly and thus allows blood to leak and have inappropriate flow of blood between the heart chambers. The prognosis for a severe defect is generally poor. Minor defects, however, may be well tolerated and even allow a normal life.

Patent Ductus Arteriosus

The most common congenital heart defects in dogs and cats are patent ductus arteriosus (PDA), is a persistent opening between the two major blood vessels leading from the heart.

Pulmonary/Subaortic Stenosis

Dogs are affected by pulmonary/subaortic stenosis (SAS) but this is rare in cats. Subaortic stenosis is a narrowing (stenosis) of the aortic valve that causes some degree of obstruction or blockage of the blood flow through the heart. Pulmonic stenosis is a narrowing (stenosis) of the pulmonary valve that causes some degree of obstruction or blockage of the blood flow from the heart to the lungs.

Ventral Septal Defect

Ventricular septal defect (VSD) is commonly found in cats and rare in dogs. Ventral septal defect occurs due to incomplete formation of the interventricular septum (lower chambers of the heart). VSD may cause a loud systolic murmur.

Degenerative Mitral Valve Disease

Degenerative mitral valve disease is degeneration of the heart valves. The heart has to work harder to pump enough blood to the body. The extra effort causes the heart muscle to weaken and gradually the left lower heart chamber (ventricle) enlarges. This is more common in dogs but in cats it’s rare. It was linked to dietary deficiency in taurine, which has been corrected by most cat food manufactures.

Pericardial Disease

Dogs and cats can be affected by pericardial disease. Pericardial effusion is a condition in which extra fluid collects between the heart and the pericardium (the sac around the heart). The extra fluid causes pressure on the heart preventing the heart from pumping normally.


Cardiomyopathy is one of the most common heart diseases in adult cat and dogs. Cardiomyopathy is brought about by a structural abnormality in the affected chamber taking on a thickened, dilated or scarred appearance. The abnormality compromises the normal pumping action of the heart and such dysfunction can progress to congestive heart failure. Three types of disease account for nearly all of the primary cardiomyopathies: Hypertrophic cardiomyopathy Developing with no explanation other than the strong likelihood of hereditary influence, hypertrophic cardiomyopathy is characterized by a thickening of the muscle tissue associated with the left ventricle. This is most common in cats. Restrictive cardiomyopathy An excessive buildup of scar tissue on the inner lining and muscle of a ventricle. This prevents the organ from relaxing completely, filling adequately and emptying with each heartbeat. Can also be characterized by severely enlarged atria and reduced cardiac filling and pumping efficiency. This is mostly found in geriatric cats.

Dilated cardiomyopathy

This third disease is rare in cats but common in dogs. It is characterized by an enlarged and poorly contracting left ventricle. The heart walls are thin and flaccid, which results in weak pumping and a reduced forward flow of blood from the heart. This disease is directly linked in studies in dogs to a grain free diet.

Congestive Heart Failure

Progressive heart failure and dysfunction of the heart due to cardiomyopathy can result in collection of fluid in or around the lungs and then to respiratory distress. This disease can be treated with diuretics and sometimes hospitalization and oxygen.

Heartworm Disease

Heartworms are transmitted by mosquitos. Heartworm larvae get into the bloodstream via mosquito bite, grow into adult worms and clog the heart and lung arteries. This disease is preventable and can be fatal if not treated. Both dogs and cats can get Heartworms however diagnostics can be tricky when diagnosing cats. Cats with suspected heartworm disease can show signs of respiratory distress similar to asthma.

Hypertension (High Blood pressure)

High blood pressure occurs when a pet’s arteries are too narrow or too stiff, making the heart work harder. There are other diseases that can cause high blood pressure in combination with heart disease.

Advance cases of cardiomyopathy in cats

Saddle thrombus - paralysis-causing blood clots, which lodge in arteries somewhere in the body, affect rear limbs or may cause sudden death. Anemia – results from lack of healthy red blood cells. This leads to reduced oxygen flow to the body organs. Anemia is commonly found in congestive heart failure pets. Hyperthyroidism – elevated thyroid hormones stimulate an increase in heart rate making the heart muscle work harder and cause thickening if the left ventricle of the heart over time.

Our team of highly skilled cardiologists are here to help. If you have concerns about heart disease in your pet you can come in through emergency. We can help determine whether your pet needs emergent attention or if your pet requires a consult/appointment with our cardiologist. If a cardiology consult/appointment is recommended then a deposit is required at the time of scheduling. Let us help your pet and give you peace of mind.