Understanding Heart Disease in Dogs

The heart is a four chambered muscular pump. There are two right and two left chambers. The top upper right chamber, called the atrium, receives oxygen depleted blood from the body through two major veins, sends it to the lower right chamber, called the right ventricle, and out to the lungs. Here the blood is replenished with oxygen, sent back to the heart's left upper chamber, called the left atrium, down to the left lower chamber, called the left ventricle, and out to the body, through blood vessels called arteries.  When the heart is significantly diseased, its pumping and delivery power are compromised and clinical symptoms develop; but if the changes in the heart are minimal there may not be any outward signs.

Some commonly seen heart diseases in dogs:

• Heart Valve Degeneration -  also called myxomatous mitral valve disease or chronic mitral valve disease. This is caused mainly by degenerative changes in the left mitral valve, which is situated between the left upper heart chamber (the atrium) and the left lower chamber (the ventricle). On physical examination this is detectable as a murmur, As the valve progressively weakens it can lead to heart failure, called congestive heart failure.
• Dilated Cardiomyopathy- progressive weakening of the heart muscle, more commonly seen in large breed dogs.
• Conditions causing abnormal heart rhythms-either leading to very slow, very rapid or very irregular heart beats. This is audible on physical examination.
• Heart based tumor - Cardiac neoplasia

Heart failure can be caused by any of the above conditions when they have progressed to the point of severely hindering the heart's ability to pump life giving blood to the body.

Signs of significantly diseased heart:

• Shortness of breath, rapid breathing, coughing. This may worse at night.
• Weakness, exercise intolerance, restlessness.
• Abdomen distended with fluid
• Poor appetite and weight loss
• Collapse or syncope (fainting spells). This is oftentimes associated with exertion.
• Death

Diagnosing and monitoring heart disease in the dog:

• Physical examination, blood chemistry, complete blood count, NT-Pro BNP assay (a protein compound that is released from heart muscle cells when they are stretched beyond normal).
• Chest radiographs
• Echocardiogram, electrocardiogram
• Regular visits with your veterinarian and/or veterinary cardiologist

Managing a dog with heart disease:

• Dietary changes which include lower sodium intake. There are well formulated prescription diets for this condition.
• Medication to help the heart muscle contract more effectively, to ease the resistance of blood flow from the heart to  the blood vessels, to remove the buildup of fluid in spaces outside of the blood vessels.  Some heart problems may require medication to slow down the heart rate or to normalize the heart rhythm.
• Exercise restriction to limit overexertion.

Treatment is tailored to the specific needs of each patient and adjustments in medication may be needed with time.

What is the prognosis for dogs with heart disease?

As with many other conditions, early diagnosis and early intervention of heart abnormalities can increase your dog’s longevity and have positive impact on the quality of life, and may extend survival time by months to years. The partnership of pet owner and veterinarian in monitoring and administering the appropriate treatments is essential.

At DR 4 PETS we believe a well informed pet owner is empowered to sustain their fur baby’s general health and thereby keep that beautiful human-pet bound alive. If however, father time or ill health brings your pet to the end-of-life we want to be there to help. We provide dignified and compassionate in-home euthanasia to the feline and canine population of Ventura, Camarillo, Thousand Oaks, Agoura, Moorpark, Simi Valley, Chatsworth, Porter Ranch, Calabasas, and neighboring communities. Give us a call at (805) 494-3339.