What is Congestive Heart Failure (CHF)?
Congestive heart failure occurs when the heart is unable to adequately pump blood throughout the body. When this occurs, blood backs up into the lungs and fluid accumulates in the body’s cavities. This further constricts both the heart and lungs and prevents sufficient oxygen flow throughout the body. There are two main types of CHF in dogs:
Right-sided congestive heart failure (RS-CHF)
This type of CHF occurs when the heart contracts and some blood leaks into the right atrium from the right ventricle through the tricuspid valve, versus being pushed through the lungs to become oxygenated. As a result, the main circulation system becomes congested with backed up blood and fluid accumulates in the abdomen, which interferes with proper organ function. Excess fluid may also build up in the limbs causing peripheral edema (swelling).
Left-sided congestive heart failure (LS-CHF)
The most common type of CHF in dogs occurs when blood from the left ventricle leaks back into the left atrium through the mitral valve, versus getting pumped into the systemic circulation whenever the heart contracts. This diminished cardiac function causes volume or pressure overload to the heart’s left side. As a result, fluid leaks into the tissue of the lungs causing pulmonary edema (swelling), which further leads to coughing and difficulty breathing.
Symptoms of CHF
Struggling to breathe
Breathing at a fast rate, especially at rest
Reluctance or refusal to exercise
Getting tired more easily on walks or during play
Coughing up blood
If any of these symptoms are present, contact your veterinarian for an exam.
The most common cause of CHF is the presence of a genetic defect. This is something that cannot be prevented. There are many small breeds that have a genetic propensity toward CHF, including toy poodles, pomeranians, dachshunds, and cavalier King Charles spaniels. Small dogs tend to be more prone to developing this condition due to the heart valves degenerating more than larger breeds. That being said, there are also some larger breeds (particularly giant breeds) such as St. Bernards, Newfoundlands, and great Danes that are prone to developing CHF. This often occurs in larger breeds due to dilated heart muscles.
It is important to understand that congenital CHF typically manifests late in a dog’s life. These dogs can live many healthy and happy years before symptoms appear.
CHF may also develop in a heart that is weakened by other heart conditions. To help prevent heart disease from occurring in your pet, it is important to prevent obesity and provide heartworm prevention.
During your pet’s exam, the detection of a heart murmur or other heart irregularity may result in your vet referring you to a veterinary cardiologist. Common tests used to diagnose CHF include chest x-rays, an electrocardiogram (this measures the electrical activity of the heart), and echocardiogram (an ultrasound of the heart). Blood and urine tests may also be ordered to rule out other possible causes of the symptoms.
If your dog is struggling to breathe, the vet may administer oxygen therapy or require hospitalization. For ongoing treatment, several medications are typically prescribed. These usually include a diuretic to remove the excess fluid buildup, an angiotensin-converting enzyme (ACE) inhibitor that has been shown to improve clinical signs and increase the odds of survival, and a vasodilator to relax the blood vessels, which allows the heart to pump blood more easily. There are some cases where a positive inotrope may also be prescribed to strengthen the force of the heart’s contractions and improve blood flow.
Medications are only a part of the treatment plan for a dog with CHF. In addition, your vet may suggest a different diet, recommend regular checkups to monitor the heart and lungs, require regular blood work, and instruct you on how to check your pet’s respiratory rate at home. They may also recommend eliminating stress in the pet’s environment and suggest monitoring your pet’s physical activities.
Regarding diet, a discussion with the vet will allow owners to gain a better understanding of their pet’s needs and how to better meet those needs. For example, your vet may suggest restricting sodium in your pet’s diet and may prescribe a prescription food with this limitation, along with also providing the pet a way of getting the right vitamins and nutrients to better improve their health.
Regarding regular checkups, our vets want to make sure we are helping maintain their condition. These regular checkups will allow us to see if any medications or lifestyle changes are needed. Monitoring kidney function is also imperative when your pet is on certain medications, such as diuretics.
The home care aspect will create a better understanding of signs and symptoms to continuously monitor along, with an explanation of what to do when these symptoms present themselves. You should discuss with your vet what to do if your pet’s respiratory rate rises above normal or if they over-exert themselves during physical activity.
There is no cure for CHF, and the goal of treatment is to improve and maintain the pet’s quality of life. Prognosis used to be poor for dogs with CHF, but advancements in medications used to treat this condition have dramatically improved the overall prognosis. Home care and lifestyle management are also just as important, as it may extend a dog’s survival from months to years. The earlier CHF is identified and treatments started, the better the chances of extending their life.
The best thing you can do for your dog throughout their life is to follow your vet’s advice. Pets should be brought in for annual checkups. Owners should ask about their nutrition including treats, water intake, exercise, and any additional care that can help them lead a healthier life.
Hill’s Pet Nutrition: https://www.hillspet.com/dog-care/healthcare/congestive-heart-failure-in-dogs