Heart Failure, Congestive (Left-Sided) in Dogs

Congestive heart failure (left-sided) in dogs is known as subaortic stenosis (SAS). This condition distresses the heart’s left side, with the opening in the middle of the left ventricle and an aorta that is too narrow, resulting in the harder, overworked left ventricle forcing the blood through this abnormally narrow area to flow into the aorta. The blood must then move forward throughout the rest of the body. The extra workload of the left ventricle is too much for it to handle over time. This condition results in an obstruction of proper flowing blood throughout the heart. Congestive heart failure (left-sided) in dogs can range from a mild to severely narrowed opening.

Congestive Heart Failure (left-sided) in dogs occurs when the heart’s left side is functioning abnormally. The left ventricle, due to a very narrow opening between the ventricle and the aorta, has a higher workload than normal.

When a dog has subaortic stenosis, he will exhibit the following symptoms. Some of the symptoms may be mild and some of them quite severe. Symptoms include:

• Lethargy
• Fainting
• Poor growth
• Weakness
• Intolerance to exercise
• Difficulty breathing
• Collapse
• Sudden death (in severe cases)

Types

Subaortic stenosis is one of the most common inherited heart defects found in puppies. Types of puppies that show a higher risk of having this condition at birth are:

• Golden Retrievers
• Newfoundlands
• Rottweilers

Subaortic stenosis is genetic. It can appear puppies or within the first year of life; puppies with this condition should not be bred.

In order to diagnose a congenital heart condition, or heart failure, such as subaortic stenosis, the veterinarian will perform a physical examination. This includes basic tests in the beginning, such as blood work, urinalysis, biochemistry profile, and the general listening of the heart via stethoscope.

After listening to explain the dog’s symptoms, he will then begin to focus on the condition of the heart. By listening to the heart he will tune into any irregular heartbeats and murmurs. He will order chest x-rays to be done, especially if the dog is having difficulty breathing. Chest x-rays may reveal a buildup of fluid in the most severe situation.

The medical professional will want to perform an electrocardiogram to look at the functionality of the heart in the electrical impulses. Abnormal heart rhythm will also be looked at. An echocardiogram is an ultrasound of the heart that will also be performed to give the veterinarian even more information. This cardiac ultrasound is the ideal test for this condition because it shows the inside of the heart as it is working. The veterinarian will be able to view the valve function, the blood flow, the quality of blood flow, and any obstruction to the flow of blood. There is even another exam, the Doppler ultrasound, that will measure the blood’s flow and direction as it goes in and out of the heart.

Treatment may not be required if your dog’s condition is very mild. This condition can become worse as the dog gets older and his body becomes larger. Treatment for this condition includes:

Medication

The veterinarian may prescribe Beta Blockers because these drugs help the heart by maintaining a lower workload upon the organ. Beta Blockers keep the heart from rapidly beating and also control any irregular heartbeats.

Lifestyle Management

Dogs with moderate to severe subaortic stenosis need to have their exercise and other exertive activity controlled. Any intense exertion or sudden and prolonged movements may cause the dog to collapse, faint, and in worst cases death may occur.

Surgery

There are a few surgical procedures that may help lessen the condition, such as a balloon catheterization; however, these surgeries are still being studied and their definitive success is variable at this time.

Your veterinarian will give you specific instructions to follow on any routines and medications you need to administer to give your dog the best care at home. The medical professional will also explain to you what you need to watch for in terms of sudden symptoms that require emergency care. In terms of administering medication, it is important to follow the instructions the veterinarian provided and to also watch for any side effects that can occur with these medications. Every dog is different, as is every diagnosis. Your veterinarian will be the one to give you an accurate prognosis for your dog’s future. In addition to any medications, a lot of love, affection, dedication, and care can work wonders for your dog’s well-being.