As the vital center of your pet’s cardiovascular system, their heart is one of their most critical organs, continuously pumping to circulate oxygenated blood to every body cell, from nose to tail tip. If disease interrupts your pet’s normal heart function, their entire body can be compromised, with a range of effects. Fortunately, VetMED’s board-certified veterinary cardiologists are skilled at diagnosing and treating all types of canine and feline heart disease, to give pets with this scary diagnosis the best chance of living long, fulfilling lives. To help you understand the types of heart problems our cardiology department can manage, we explain the five heart diseases our cardiology team treats the most.

#1: Valvular Degeneration

Your cat or dog’s heart, which is anatomically similar to a human heart, is composed of four chambers—two on each side—with valves that open and close to regulate blood flow. Valves are situated between each upper chamber (i.e., the atria) and lower chamber (i.e., the ventricle), and at the exit from each lower chamber. As pets age, their heart valves can deteriorate to the point where they no longer close completely, and their blood fails to flow in the right direction. 

Degenerative mitral valve disease (DMVD) is the most common type of valvular degeneration to affect dogs. As dogs age, the mitral valve—the valve separating the left atria from the left ventricle—thickens and becomes weaker, allowing a small amount of blood to flow backward through the valve with each heartbeat. This backward flow of blood is called mitral valve regurgitation. As mitral valve regurgitation increases, progressive heart enlargement can occur, and dogs become at risk of developing congestive heart failure (CHF). DMVD typically affects older, small-breed dogs. Most dogs have mild disease, but approximately 30% may experience more severe disease that requires life-long management. DMVD is often diagnosed when your family veterinarian detects a left-sided heart murmur during a routine physical exam. The VetMED cardiology team will then assess the severity of your pet’s valvular degeneration, and formulate a treatment plan that will successfully manage the condition.

#2: Dilated cardiomyopathy (DCM)

DCM is a family of diseases in dogs that results in weakening of the heart muscle. As a result, less blood is pumped out of the heart with each heartbeat, causing the walls to stretch and the chambers to dilate, or become larger, placing dogs at risk of developing CHF. DCM most often affects large- and giant-breed dogs, with some breeds at higher risk, including:

• Doberman Pinschers
• Boxers
• Great Danes

Unfortunately, naturally occurring DCM is irreversible and progressive. With a prompt diagnosis, and our cardiology team’s expertise, we can prolong symptom-free life,  improving your beloved companion’s quality of life. 

DCM has received recent attention due to a potential link to grain-free pet diets. The Food and Drug Administration (FDA) is investigating an increased incidence in DCM in dogs, and diets that use an alternate carbohydrate source appear to be one of the common factors. The investigation is on-going, and the FDA has not yet established the exact cause of DCM in these apparent diet-related cases. Consultation with a member of our cardiology team can help determine whether or not your pet has DCM and what diet would be the best for them.

#3: Hypertrophic cardiomyopathy (HCM)

HCM, which is the most commonly diagnosed heart disease in cats, results from an abnormal thickening of the left ventricular muscle, which decreases the ventricle’s ability to relax and accept blood. As a result, pressure within the heart increases, causing dilation of the heart, and increased risk of CHF development. Blood flow can become sluggish, increasing the risk of blood clot formation. Blood clots that form in the heart may leave and cause blockages, most commonly in the back legs.

Unfortunately, cats are masters at hiding illness, and HCM is often silent. Cats rarely show symptoms until CHF develops, or a clot blocks blood flow to their back legs, causing sudden, intense pain, and possible paralysis. Regular physical exams are particularly important in cats, so your family veterinarian can screen for heart disease signs. If your family veterinarian suspects that your cat may have HCM, the VetMED cardiology team can perform a cardiac workup to determine if the disease is present, and if medications are indicated. Although HCM is not curable, many affected cats live their entire lives without developing CHF or blood clots, with proper disease management. 

#4: Heart arrhythmias

Each of your pet’s heartbeats is initiated and controlled by an electrical impulse that travels through the heart muscle. Each impulse begins in the top part of the heart, and travels through a specialized conduction pathway, causing a coordinated heart contraction. If these electrical impulses fail to initiate properly, follow the correct pathway, or move through the entire conduction system, an abnormal heart rhythm (i.e., arrhythmia) may develop. Common arrhythmias in pets include:

• Tachycardia, or an increased heart rate
• Bradycardia, or a decreased heart rate
• Premature ventricular contractions
• Heart block
• Atrial fibrillation

Your family veterinarian can detect an arrhythmia during a physical exam. Common symptoms you may see at home include weakness, lethargy, exercise intolerance, or collapse. If an arrhythmia is suspected, our cardiologists can perform an electrocardiogram (ECG) to evaluate the heart’s electrical activity. Often, we have a patient wear a Holter monitor (i.e., a harness containing an ECG-recording device that records heart activity over 24 hours), so we can fully appreciate the arrhythmia’s extent and frequency. Depending on the diagnosis, treatment may include oral antiarrhythmic drugs or pacemaker therapy.

#5: Congenital Heart Disease

Congenital heart diseases, which result from abnormal heart development, and are present from birth, account for approximately 3% to 5% of the cases our cardiology service sees on a yearly basis. These diseases are typically diagnosed when your family veterinarian detects a heart murmur during your puppy or kitten’s exam. A prompt ultrasound of the heart, performed by our cardiology team, can help us determine which congenital heart disease is present, so we can provide the best treatment recommendations, before the disease progresses. Common congenital heart diseases include:

• Patent ductus arteriosus (PDA)
• Pulmonic stenosis
• Subaortic stenosis
• Ventricular septal defect (VSD)

Depending on which congenital heart disease is present, minimally invasive surgery may be able to improve or correct the abnormality. Minimally invasive procedures are performed by our cardiology team, using catheters passed through large blood vessels. In many cases, pets recover quickly from these procedures, and go on to live full, happy, and healthy lives.

If your family veterinarian has diagnosed heart disease in your pet, contact the VetMED cardiology department, so we can use our advanced tools and expertise to help your best friend live as long, and be as healthy, as possible.