DOGS · Condition guide
Myxomatous mitral valve disease in dogs: what real veterinary cases show
Myxomatous mitral valve disease (MMVD) is a common heart condition in dogs, particularly in small breeds. It occurs when the mitral valve, which separates the left atrium and left ventricle of the heart, becomes thickened and deformed, leading to improper closure. This results in blood leaking backward into the left atrium, a condition known as mitral regurgitation.
Owners often first notice a heart murmur during a routine veterinary check-up, which can be an early sign of MMVD. Early detection is crucial as it allows for monitoring and management before the condition progresses to heart failure, significantly affecting a dog's quality of life.
What vets typically check for
- Auscultation to detect heart murmurs.
- Thoracic radiographs to assess heart size and shape.
- Echocardiography to evaluate valve structure and function.
- Blood pressure measurement to check for hypertension.
- Medical management with medications like ACE inhibitors and diuretics.
Not a replacement for veterinary care. Use this to walk into the conversation prepared, not to self-diagnose.
Real cases from the veterinary literature
Peer-reviewed reports our semantic search surfaces for Canine myxomatous mitral valve disease (MMVD). Click into any case for the full abstract — or run a personalised search with your pet's exact details.
- Association between morphometric measurements and disease progression in Cavalier King Charles Spaniels with preclinical degenerative mitral valve disease: A retrospective longitudinal study.
PloS one · 2026 · Italy
A group of Cavalier King Charles Spaniels (CKCS) with early signs of heart disease were monitored over two years to see how their body shape affected the progression of their condition. The study found that certain measurements, like the length and circumference of their chest, were linked to how quickly their mitral valve disease (MMVD) got worse. Out of 52 dogs, about one-thi
- Association of pulmonary arterial end-diastolic forward flow and right heart remodeling in dogs with congenital pulmonic stenosis and precapillary pulmonary hypertension.
Journal of veterinary cardiology : the official journal of the European Society of Veterinary Cardiology · 2026 · United States
A group of dogs with congenital heart issues, specifically pulmonic stenosis (a narrowing of the heart valve) and precapillary pulmonary hypertension (high blood pressure in the lungs), showed higher blood flow measurements in their main pulmonary artery compared to healthy dogs. This increased blood flow was linked to changes in the structure of the right side of their hearts,
- Exploring the therapeutic potential of β-nicotinamide mononucleotide (NMN) in regulating canine NT-proBNP levels
Journal of Advanced Veterinary and Animal Research · 2026 · BD
A group of dogs with high NT-proBNP levels, a marker for heart problems, were given an oral supplement called β-nicotinamide mononucleotide (NMN) to see if it could help lower these levels. The dogs received doses adjusted to their weight twice daily until their NT-proBNP levels returned to normal. The results showed that NMN significantly reduced NT-proBNP levels in dogs witho
- Right and left heart morphology and function in dogs with compensated chronic right ventricular pressure overload secondary to pulmonic stenosis or precapillary pulmonary hypertension.
The Canadian veterinary journal = La revue veterinaire canadienne · 2026
A group of dogs with heart issues, specifically those with pulmonic stenosis (a narrowing of the heart valve) and chronic precapillary pulmonary hypertension (high blood pressure in the lungs), were studied to see how their hearts were functioning. The dogs with pulmonic stenosis had less dilation of the right ventricle and better overall heart function compared to those with p
- Anaesthetic management and peri-anaesthetic morbidity and mortality in a population of 176 dogs undergoing mitral valve repair under cardiopulmonary bypass.
Frontiers in veterinary science · 2026 · United Kingdom
A group of 176 dogs undergoing surgery to repair a heart valve experienced significant complications during and after the procedure. The surgery involved using a heart-lung machine (cardiopulmonary bypass), and unfortunately, about 20.5% of the dogs did not survive to go home, with some complications proving fatal despite treatment. Factors like lower body weight and longer sur
- Outcomes of mitral valve repair in dogs with myxomatous mitral valve disease and preoperative atrial fibrillation.
Journal of veterinary internal medicine · 2026 · Japan
A group of 28 dogs with heart problems, specifically myxomatous mitral valve disease and preoperative atrial fibrillation (a type of irregular heartbeat), underwent surgery to repair their mitral valve. After the surgery, 14 dogs returned to a normal heartbeat, while 10 continued to have atrial fibrillation. The survival rate was high in the first month after surgery, but those
Frequently asked questions
- What are the symptoms of MMVD in dogs?
- Symptoms can include coughing, difficulty breathing, reduced exercise tolerance, and fainting. However, some dogs may show no symptoms in the early stages.
- How is MMVD diagnosed?
- Diagnosis typically involves a combination of physical examination, listening for heart murmurs, and imaging techniques such as X-rays and echocardiography to assess heart function.
- Can MMVD be cured?
- While there is no cure for MMVD, it can often be managed with medications that help control symptoms and slow disease progression, improving the dog's quality of life.