Does your furry best friend have mitral valve disease? If so, you are not alone. This heart condition is most common in dogs, especially older small-breed dogs. But what exactly is mitral valve disease in dogs, and what can you do to salvage the situation?
In this blog post, we will explore the causes, symptoms, and treatment options for mitral valve disease in dogs. We will also share tips on managing your dog’s condition and improving their health and happiness.
What is Mitral Valve Disease?
Mitral valve disease is a progressive disorder caused by the deterioration of the mitral valve. This valve is between the left atrium and ventricle and helps regulate blood flow. When it damages, blood flows in both directions through the valve instead of one way. This increases pressure within the heart’s chambers, resulting in lung enlargement.
Dogs with this condition can show signs such as coughing, shortness of breath, and exercise intolerance.
The disease is most common in older, smaller breed dogs, which may be prone to develop it at an earlier age. Treatment for this condition usually involves medications that help support weak valves. However, some cases need surgery if symptoms do not improve with medication alone.
Causes of Mitral Valve Disease in Dogs
The exact cause of this condition and the associated degeneration are unknown. Yet, current theories suggest that an underlying genetic defect may cause it.
This theory has been supported by research into the genetics of certain dog breeds, as isolated cases of mitral valve disease appear to be linked to specific genetic variants in individual breeds. Studies have also suggested that other factors, such as age and gender, could increase dogs’ risk of developing this condition. Environmental factors such as exposure to toxins or pollutants may also play a role in contributing to its development.
Ultimately further research is needed on this topic to identify its root cause in individual breeds of dogs more accurately.
Symptoms of Mitral Valve Disease
The primary symptom of this condition is a heart murmur that can be heard during a physical examination with a stethoscope. As the disease progresses, additional symptoms may include coughing, exercise intolerance, increased respiratory rate, and panting.
These clinical signs often indicate congestive heart failure, wherein fluid accumulates in the lungs due to increased pressure within the chest cavity. Unfortunately, as mitral valve disease progresses, it becomes difficult to manage.
Diagnosis of Mitral Valve Disease
Diagnosing MVD begins with a physical examination. A heart murmur heard by a stethoscope during the physical exam may indicate MVD. In addition to a physical exam, other tests may be needed to assess the severity of MVD.
Chest X-rays or an echocardiogram (ultrasound of the heart) can provide images to help identify any enlarged heart chambers or leaky valves. Vets may also perform a blood test for heart disease (NTproBNP) to assess the severity of MVD.
In most cases, imaging tests such as chest X-ray or echocardiograph diagnose further and monitor MVD. The imaging results indicate how severe the damage is to the valve and if abnormalities are present in any of the four chambers of your heart. The vet will use these results and your dog’s overall medical history and symptoms to determine if it has MVD.
There are four different stages of mitral valve disease. Here’s a bit more information about each stage:
Stage A: This is the earliest stage of heart disease in dogs, where the animal is at high risk of developing the condition due to factors such as breed, age, or other health issues.
Stage B1: A heart murmur can be detected during a veterinary exam, but there are no signs of heart failure or enlargement.
B2: Similar to Stage B1, a heart murmur is present, but there is evidence of heart enlargement.
Stage C: In this stage, the heart disease has progressed, and symptoms such as coughing, difficulty breathing, and exercise intolerance become more evident.
Stage D: This is the final stage of heart disease, where the dog’s condition is not responding to treatment, and the quality of life reduces. At this point, the goal of treatment shifts from managing symptoms to providing comfort and palliative care.
Complications of Mitral Valve Disease
One of the main complications is congestive heart failure (CHF). As the mitral valve becomes damaged and weak, it fails to close properly, causing blood to leak backward into the left atrium. This increases pressure in the heart and lungs, leading to fluid accumulation and the development of CHF.
Another complication is the formation of blood clots. When the blood flow is disrupted due to abnormal valve function, blood pooling, and turbulence can occur. This creates an environment conducive to clot formation.
If a clot dislodges and travels to other parts of the body, it can cause serious issues, such as a stroke or organ damage.
Also, mitral valve disease can cause enlargement of the heart chambers and weakened heart muscle. The heart has to work harder to pump blood efficiently. And this causes progressive heart enlargement and reduced cardiac function.
Other complications may include arrhythmias, pulmonary hypertension, and secondary damage to other organs due to reduced blood supply and oxygenation.
Treatment of Mitral Valve Disease
Medical management is a key part of treating mitral valve disease. It includes careful monitoring of the condition and medication to help slow the disease’s progression. Pimobendan commonly treats symptomatic cases in stages C and D.
In addition, diuretics, ACE inhibitors, and spironolactone are effective treatments for managing congestion. In more severe cases, hospitalization may be necessary for initial treatment.
Interventional management may also reduce symptoms associated with mitral valve dysfunction using a V-Clamp device. This device helps lessen the amount of mitral regurgitation by bringing the center of the valve leaflets together. This method, called a trans-catheter edge-to-edge repair, has proven safe and effective.
Mitral valve disease in dogs is a common and often serious heart condition in smaller breeds. While there is no cure for this disease, early detection and appropriate management can greatly improve a dog’s quality of life and prolong its lifespan.