Degenerative Mitral Valve Disease (DMVD)
Overview
Degenerative mitral valve disease is the most common acquired heart disease in dogs with clinical signs including a heart murmur. Pathophysiological changes to the heart may include dilation (widened chamber) of the left ventricle, enlargement of the left atrium and pulmonary hypertension (respiratory distress and fainting).
Breeds that are predisposed:
- Miniature Poodle
- Cavalier King Charles Spaniel
- Chihuahua
- Dachshund
Middle-aged to older small to medium sized dogs are more likely to have an acquired adult-onset heart disease. In the case of the Cavalier King Charles Spaniel, the risk increases with age but can occur as young as 4 years of age.
Diagnosis
Diagnostic workup usually includes a combination of:
- Physical examination
- Echocardiography (ultrasound of the heart)
- Chest xrays
- Blood tests
Management
If your pet is showing symptoms of heart disease or is in heart failure, medications may include:
- Pimobendan
- ACE inhibitor
- Frusemide
Medication helps to control the clinical signs to slow down disease progression. Unfortunately it will not treat the valve problem. It is important that your pet is eating properly and taking their medication. Avoid high-salt foods and treats.
Many older pets may have concurrent problems such as kidney disease. In these cases, care must be taken when selecting the medication therapy due to potential adverse effects on heart medication and other drug interactions.
It is also recommended that you take regular sleeping respiratory rates at home. An elevated respiratory rate that is repeatable within the hour will require urgent medical attention.
Rechecks
Regular vet visits at least every 2-6 months depending on the severity of signs is recommended to check the pet’s response to treatment and determine whether the medications require adjustment.
Prognosis
Most dogs will not be affected in terms of their lifespan. The rate of disease progression does vary between cases. It has been estimated that is takes years before congestive heart failure develops.
Not all dogs with DMVD will progress to heart failure. Although dogs with an enlarged heart are at a greater risk of heart failure, it is estimated that only 30% of dogs with asymptomatic DMVD will develop clinical signs and require therapy.
If your pet does have congestive heart failure, they can lead a good quality of life with treatment and most survive for an additional 12-18 months.
When to seek veterinary care
- New or worsening cough
- Breathing problems
- Off food
- Vomiting
- Lethargy
- Collapse