Mitral Insufficiency In Dogs: Causes, Symptoms And Treatment

L ‘ insufficiency mitral in dogs produces different disorders that lead to degeneration or to deformation of the mitral valve. It can also be called  mitral regurgitation or mitral valve insufficiency (IVM). Given the importance of this pathology, we have decided to dedicate an article to this health problem that can also affect your dog. It is very important to know more.

The heart mechanism and the importance of heart valves

The main structure of the heart is divided into two sides – right and left – and contains four “chambers”. The two upper chambers are called the atria and the two lower chambers are called the ventricles .

The blood that reaches the heart from the body penetrates through the right atrium and passes to the right ventricle. From there, it is led to the lungs to release carbon dioxide and absorb oxygen.

Blood flow and valves

The already oxygenated blood returns to the heart, enters through the left atrium and passes to the left ventricle. At that moment it is pumped through the artery of the aorta to “feed” the entire body.

Heart valves are located between the ventricles and atria, and their function is to control the flow of blood through the heart chambers. This allows for heart rate and regular blood transmission.

The mitral valve is located on the left side of the heart and separates the left ventricle from the left atrium. Its main function is to prevent oxygenated blood from returning to the atrium and being pumped by the ventricle.

On the right side we find the tricuspid valve, where the blood circulates to be filtered. Its action allows blood to flow to the lungs to be oxygenated and not get stuck in the atrium.

What is mitral regurgitation in dogs?

We speak of insufficiency when a structure or an organ fails to fully perform its functions due to some anomaly. This disorder can be caused by internal factors or develop due to the presence of other external conditions.

In the case of the mitral valve, insufficiency occurs when the structure does not close properly. This prevents oxygenated blood from being pumped out of the body, as it returns to the left atrium.

To try to preserve organic balance, the body performs some maneuvers to ensure oxygenation of tissues and organs. However, the intensification of vascular and cardiac deficiency usually goes far beyond these automatic mechanisms ,  which are only  palliatives .

Causes of Mitral Regurgitation in Dogs

The specific cause that triggers mitral valve deformation is still unclear. Many specialists argue that its origin depends on a systemic alteration of collagen production and that it can even have a hereditary influence.

It is known that the ‘ aging is a natural factor that can lead to the weakening of the cardiac structures. Furthermore, pregnancy is also considered a possible cause of valve degeneration in female dogs.

Reasons and factors influencing mitral regurgitation in dogs

Mitral insufficiency is also associated with the following conditions :

• Mitral valve prolapse.
• Damage to the tendons that connect the mitral valve to the heart.
• Heart murmur and altered cardiovascular rhythm.
• Infection of the heart valves (endocarditis).

• Radiotherapy.
• Injuries.
• Rheumatic fever.
• Deformations in the heart muscle (cardiomyopathy).
• Congenital disorders .
• Prolonged use of ergotamine- based drugs .

Symptoms of Heart Failure in Dogs

Its most obvious symptom is usually the accumulation of fluid in different parts of the body, which generates typical swelling. Very often, the animal has a “pot-bellied” appearance due to abdominal dilation.

Next, we list other characteristic symptoms of heart failure in dogs:

• Tiredness, lack of interest and weakness.
• Cough and difficulty breathing
• Alteration of heart rate.
• Difficulty in performing physical exercise.
• Gums, mucous membranes that take on a strange  gray or blue color.
• Fainting (or syncope).
• Collapse.

If the insufficiency also affects the tricuspid valve, the dog can have complications in the liver and spleen. In addition, signs of bloating and accumulation of abdominal fluid ( ascites ) may be observed .

How to cure mitral regurgitation in dogs

When you recognize any of the above symptoms, it is essential to go to the vet immediately. The professional will proceed with the analysis of the animal in order to diagnose the cardiac anomaly and thus establish an adequate treatment.

If the state of the disease permits, the doctor may suggest surgery that will be used to recompose the mitral valve. In addition, medications are usually given to strengthen the contraction of the heart muscle.

When there is fluid accumulation in the lung or abdomen, controlled aspirations should be performed. Even the diuretics can be administered to encourage their natural elimination and the proper functioning of the valves.

Finally, when mitral regurgitation in dogs is particularly severe, the animal usually requires hospitalization and emergency oxygen therapy.