Stages of Mitral Valve Disease in Dogs - Diagnosis, and Prevention

MVD, or mitral valve disease, is a heart problem and is very common, especially among small-sized breeds and older dogs.

Canine MVD progresses due to degenerative factors, including the backflow of blood from the left atrium to the left ventricle. If unmonitored, this may change to other complex conditions and stages; ultimately, your dog's heart will fail.

This article greatly helps in the early diagnosis of the disease and its treatment. Also, the blog post clearly explains the stages of mitral valve disease in dogs, enabling you to catch the disorder initially and save your furry friend's life.

What is Mitral Valve Disease?

It is a serious heart valve disease in dogs that causes a mitral valve to leak blood.

The MVD disorder is counted for about 70 to 75% of all heart diseases in dogs. It is commonly known as Myxomatous Mitral Valve disease (MMVD). 

Brachiocephalic and dwarf breeds, Cavalier King Charles spaniels, Dachshunds, and mini-Poodles are greatly prone to the disease. 

The good side is that those dogs who receive treatment early have a lower chance of progressing the disease to further stages. 

Four Stages of Mitral Valve Disease in Dogs

According to the American College of Veterinary Internal Medicine (ACVIM) guidelines, the progression of MVD is classified into four stages.

Stage A: At Risk

Dogs in Stage A are predisposed to MVD due to their breed or family history but show no clinical signs or detectable heart abnormalities. This stage focuses on proactive care and monitoring to prevent disease progression.

Key Points:

• Commonly affected breeds include Cavalier King Charles Spaniels and Miniature Poodles.
• Dogs in this stage have no detectable heart abnormalities or symptoms.
• Regular veterinary check-ups are essential for early detection.
• Genetic predisposition plays a significant role in Stage A classification.
• Preventive care strategies include maintaining a healthy weight and providing a balanced diet.

Stage B: Early Disease

Stage B is divided into B1 and B2 based on the presence or absence of heart enlargement. Dogs in this stage may have detectable valve abnormalities but do not exhibit symptoms of heart failure.

Stage B1:

• Valve thickening or irregularities are visible through echocardiography.
• No clinical signs or heart enlargement are present.
• Monitoring every 6-12 months is recommended.
• No medications are typically prescribed at this stage.
• Early diagnosis helps plan preventive strategies.

Stage B2 heart valve disease in dogs:

• Heart enlargement is detected, indicating disease progression.
• Symptoms may include reduced stamina or slight fatigue.
• Medications such as pimobendan may be introduced to slow progression.
• Regular imaging and blood pressure monitoring become crucial.
• Dogs should avoid strenuous activities to prevent stress on the heart.

Stage C: Congestive Heart Failure

Stage C marks the onset of clinical signs of heart failure. 

In this stage, dogs are likely to experience coughing, labored breathing, and fatigue due to fluid buildup in the lungs or abdomen. As soon as you notice, get immediate veterinarian help. Moreover, it is crucial in the stages of mitral valve disease in dogs as it decides whether the dog is dying or whether there is a chance of recovery. 

• Key Points:
• The dog patient may cough, breathe fast, and feel lethargic.
• Patients often have fluid in their lungs (pulmonary edema).
• Management includes diuretics, ACE inhibitors, and pimobendan.
• It is important to monitor and conduct X-ray limb pesticide reviews.
• Lifestyle changes include following a low-sodium diet and stress management.

Stage D: End-stage of the disease

At Stage D, the dog is not responding to any form of treatment and has developed advanced congestive heart failure. 

In this case, the focus is making the dog as comfortable as possible while maintaining a good quality of life.

• Patients exhibit signs of severe labored breath, abdominal enlargement (ascites), extreme weakness, and bedridden.
• Life expectancy post-diagnosis is short, say about weeks to months.
• Medications are changed to address such symptoms and discomfort.
• The focus is on the management of pain and the reduction of the patient's stress levels.
• Other supportive therapies may include draining of fluids.

How Quickly Does Mitral Valve Disease Progress in Dogs?

The rate of progression depends on the individual dog and the stage at diagnosis. If monitored and managed appropriately, dogs in Stages A and B can live for years without significant symptoms. 

However, progression from Stage C to Stage D can occur within months, emphasizing the importance of early intervention.

What Is the Prognosis for a Dog with Mitral Valve Disease?

The prognosis varies by stage:

• Stages A and B: Favorable with regular monitoring and preventive care.
• Stage C: Life expectancy depends on the response to treatment, typically ranging from 6 months to 2 years.
• Stage D: Prognosis is poor, with an emphasis on palliative care.

How to Diagnose Mitral Valve Disease in Dogs

MVD diagnosis is a multifaceted work that involves clinical history and physical examination, imaging studies, and laboratory analysis. 

Identifying the disorder in the earlier stages ensures slowing down the disease progression rate and its conversion to other stages.

Let us look at the proper steps for diagnosing MVD in dogs. 

History and Clinical Examination

• Heart, which is affected by MVD, has a murmur. So, ask the patient’s owner if the dog has a gallop, and then, using a stethoscope, check if there is any murmuring sound.
• Ask about any respiratory symptoms that may include cough, increased respiratory effort, or even inactivity.
• Examine the dog closely if it is dehydrated, overweight, out of breath, or inactive altogether.

Echocardiography

• Use echocardiographic methods to determine the heart's structure, which will allow you to understand how the mitral valves work.
• MVD may lead to blood leakage due to valve deformity and subsequent prolapse, congestive heart failure, or valve hypertrophy; take note.
• Using echocardiography, take note of heart enlargement as well as the level of degeneration of the valve.

Thoracic Radiographs (X-rays)

• One way to know if the heart is enlarged is by taking chest X-rays to ascertain if there is any fluid in the lungs (pulmonary edema).
• This outline controls the shape and size of the heart and can assist in determining MVD rule-out.

Biomarker Testing

• Blood tests such as NT-proBNP (N-terminal pro-b-type natriuretic peptide) help veterinarians screen heart stress levels and prognosis.
• Collect blood samples periodically for routine investigations in order to rule out other systemic conditions that simulate cardiac disease.

Treatment Options for Stages of Mitral Valve Disease in Dogs

Effective management of mitral valve disease (MVD) involves medications, lifestyle adjustments, and, in some cases, surgery. Here are four key treatment options:

1. Medications
   • Pimobendan to improve heart function.
   • ACE inhibitors to reduce blood pressure.
   • Diuretics to manage fluid buildup.
2. Lifestyle Adjustments
   • Low-sodium diet to reduce fluid retention.
   • Weight management to reduce strain on the heart.
   • Stress reduction to prevent worsening symptoms.
3. Surgical Intervention
   • Valve repair or replacement in specialized centers.
4. Regular Monitoring
   • Routine vet check-ups to track disease progression.

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• Time: 8:00 PM (US Eastern Time)
• Category: Emergency/Critical Care, Cardio/Resp
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To Sum Up

Detecting the disorder in the early stages of mitral valve disease in dogs significantly reduces its progression and prevents it from reaching the final stage. 

By staying informed and attending the upcoming webinar on clinical tips for managing heart failure, you can continue to refine your skills and ensure the best possible care for your canine patients facing this critical condition.

If you want free veterinary education and resources, join the Vet and Tech platform. We offer insightful webinars that enable you to learn and earn free RACE-approved CE credits. 

Furthermore, our blog and news sections provide accurate and up-to-date information on the industry, such as career and educational guidance. 

FAQs

How do you treat mitral valve disease in dogs?

The treatment for MVD varies; however, the common treatment involves medications like: 

• Pimobendan 
• Diuretics
• Ace inhibitors
• Lifestyle adjustments such as a low-sodium diet

What is the life expectancy for a dog with mitral valve disease?

The life expectancy for dogs varies from years to months in the case of MVD stages. 

• Early Stages: Dogs can live for several years.
• Moderate Stages: 1 to 3 years.
• Advanced Stages: Life expectancy can range from a few months to a year.

However, the treatment provided and care greatly improve life expectancy.

What are the final stages of mitral valve disease in dogs?

The final stages (Stage D) involve severe heart failure symptoms, with palliative care focused on managing discomfort and providing quality of life.