What is mitral valve disease?  

Degenerative mitral valve disease is a condition where the leaflets of the valve in the heart grow thickened and nodular. This causes mitral valve regurgitation and volume overload of the left side of the dog’s heart. Mitral valve disease is a common reason behind congestive heart failure in dogs and mitral valve insufficiency is actually the most common acquired cardiac disease in old dogs. In dogs age 10 years and older, 1/3 will suffer from mitral valve insufficiency.

Cavalier King Charles Spaniel dogs are at high risk of having an inherited form of mitral valve disease that make them predisposition for developing mitral valve disease while still being fairly young. Other breeds associated with a higher incidence of mitral valve disease are Beagle, Bull Terrier, Cairn Terrier, Chihuahua, Dachshund, Dobermans, German Shepherd, Great Dane, Miniature Papillion, Pinschers, Pekinese, Whippets, and all 3 sizes of Poodles. As you can see, a majority of these dogs are small breeds.

Mitral valve disease symptoms in dogs

The first symptom of mitral valve disease is usually heart murmur. The presence of heart murmur does not mean that the dog is severely ill; it is only a condition that might develop into mitral valve disease. Many dogs with diagnosed heart murmur live full life spans. Even dogs that develop heart murmurs at an early age can become just as old as the breed normally does. Heart murmurs can be caused by a wide range of different health problems of which mitral valve problem is one. In order to diagnose mitral valve disease, the veterinarian needs to establish where the regurgitation is heard.

In cases of mild heart murmur, the dog will normally display no symptoms at all, except for the sounds that the vet can hear when listening to the heart. If mitral valve disease progresses, the symptoms can include more audible murmurs, weakness, intolerance of exercise, and an increased respiratory rate. Eventually, fluid can start accumulating in the lung of the dog, leading to laboured breath and coughing.

Mitral valve disease treatment for dogs?

Heart murmurs in dogs are graded from 1 to 6, where grade 1 indicates mild heart murmur and grade 6 stands for severe heart murmur. The correct treatment will depend on the severity of the heart murmur, combined with other symptoms displayed by your dog.

As long as the mitral valve disease only causes mild heart murmur, it can be treated with dietary changes. Keeping your dog on a diet low in sodium is important. Some breeders of Cavalier King Charles Spaniel dogs have noticed improvements when giving their dogs Co-enzyme Q10, but this treatment has not been scientifically confirmed for dogs. A number of studies have however showed that Co-enzyme Q10 can be used to improve the condition for patients with certain types of cardiac disease.

If the mitral valve disease progresses even further, diuretic and vasodilating medications can be administered to the dog to prevent coughing and laboured breathing.

Cardiovascular and circulatory problems in dogs: (click for more info)
Aortic stenosis in dogs
Congestive heart failure in dogs
Degenerative mitral valve disease in dogs
Dilated cardiomyopathy in dogs
Heart valve dysplasia in dogs
Hemolytic anemia in dogs
Patent ductus arteriosus in dogs
Pericardial effusion in dogs
Pulmonary hypertension in dogs
Pulmonic stenosis in dogs
Thrombocytopenia in dogs
Ventricular septal defect in dogs
Atrial septal defect in dogs
Tetralogy of Fallot in dogs
Von Willebrand disease in dogs