Treatment and detection of congestive heart failure in dogs

Disclaimer: This article, its content, and its related references do not constitute veterinary advice and should not be considered a substitute for veterinary care. If your pet is showing any symptoms that could indicate a medical emergency, please seek immediate emergency care.

Congestive heart failure (CHF) is a common condition in dogs in which the heart can no longer pump blood efficiently, resulting in a buildup of fluid elsewhere in the body, which may cause difficulty breathing, a swollen belly, and other signs of illness. Early clinical signs can be subtle, so it’s important for dog owners to notify a veterinarian any time their dog has changes in their physical condition or normal behavior, even if those changes are minor. Read on to discover:

• What congestive heart failure is and how it develops
• Symptoms of heart failure in dogs
• Treatment methods for canine congestive heart failure

CHF shares common symptoms with other conditions, so an accurate diagnosis is needed to start proper treatment. The condition is often progressive and cannot be cured, but symptoms can sometimes be managed through medication, fluid drainage, and surgery. While some dogs live for years with a good quality of life, CHF can also come on suddenly with severe, life-threatening symptoms. CHF is caused by other heart conditions, such as dilated cardiomyopathy, mitral valve disease, and congenital heart defects.

Congestive heart failure (CHF) is a condition in which a dog’s heart cannot pump blood efficiently, resulting in a buildup of fluid in the chest, the abdomen, or both. When the heart is not pumping efficiently, pressure increases in the blood vessels upstream of the diseased part of the heart. This pressure overload causes fluid to leak outside of the blood vessels and into other parts of the body.

CHF can be classified in different ways based on:

• Its underlying cause (congenital or acquired heart disease)
• Which sides of the heart are affected (left, right, or both)
• Whether its acute or chronic

Each side of the heart has a different job. The left side of the heart pumps oxygenated blood from the lungs to the body, while the right side pumps blood returning from the body to the lungs. As a result, left-sided congestive heart failure results in fluid buildup in the lungs, while right-sided congestive heart failure results in fluid buildup in the abdomen.

Most cases of CHF have a slow onset, but the disease can be acute, with sudden, emergency symptoms. Additionally, dogs with chronic CHF tend to adjust to the lack of efficient circulation and may appear to be doing fine until something changes and severe symptoms develop. Congestive heart failure in dogs is common and usually can’t be cured. However, medications can relieve symptoms, and many affected dogs maintain a good quality of life for months, with some doing well for a year or longer.

How dogs develop congestive heart failure

CHF develops secondarily to various types of heart disease. It’s important to note that not all dogs with heart disease will develop CHF. Any condition that decreases the heart’s capacity to pump blood can lead to CHF. Leaky heart valves (valvular insufficiency), heart muscle diseases (cardiomyopathies), and congenital heart defects are the most common causes of CHF in dogs. The most common canine heart conditions that can lead to CHF include:

• Mitral valve disease (mitral valvular insufficiency, MVI)
• Dilated and hypertrophic cardiomyopathy (DCM and HCM)
• Congenital heart diseases
• Heartworm disease
• Disorders of the sac surrounding the heart (pericardial disease)

Other than heartworm disease, most causes of CHF can’t be prevented. It’s important for dogs with heart disease to receive regular checkups with a veterinarian to best manage their condition.

Clinical signs of heart failure can vary depending on how severe or advanced the condition is and which side of the heart is affected. Early signs of left-sided congestive heart failure result from the buildup of fluid in the lungs and include:

• Mild, persistent cough
• Lower activity level than usual
• Increase in resting respiratory rate

Early signs of CHF in dogs may be subtle and difficult for pet parents to detect. As left-sided heart failure progresses, additional symptoms develop, including:

• Panting at rest
• Exercise intolerance
• Lethargy
• Difficulty breathing
• Blue gums
• Collapse
• Loss of consciousness

Clinical signs of right-sided congestive heart failure result from the buildup of fluid in the abdomen and can include:

• Distended, swollen abdomen
• Signs of discomfort while lying down
• Lethargy
• Loss of appetite
• Difficulty breathing
• Blue gums
• Loss of consciousness

Dogs can have both left- and right-sided heart failure at the same time. Symptoms of the disease can be made worse with exercise or being at a high elevation. End-stage CHF usually results in emergency symptoms such as difficulty breathing and blue gums.

Health conditions with similar clinical signs

There are many noncardiac health conditions that have similar symptoms to CHF, symptoms such as exercise intolerance, coughing, lethargy, and a bloated abdomen. These conditions include:

• Obesity
• Kennel cough (bordetella)
• Fungal infections
• Brachycephalic airway syndrome
• Tracheal collapse
• Hypothyroidism
• Cushing’s disease

It’s important to get an accurate diagnosis from a veterinarian because so many medical conditions share common symptoms but are treated differently.

How dogs with congestive heart failure are diagnosed

Dogs with CHF may present with varying symptoms depending on the severity of the disease, its underlying cause, and what part of the heart is affected. Diagnosing a dog that has a chronic cough or other common sign of CHF requires testing to identify the underlying cause of the symptom. Diagnostic tests may include:

• Physical exam
• Blood tests, including a ProBNP to identify heart muscle damage
• Chest X-rays
• Electrocardiography or echocardiography (ECG or heart ultrasound)
• Fluid analysis from the chest or abdomen

Dogs in CHF often have elevated resting respiratory and heart rates as well as a detectable heart murmur in a physical exam. A chest X-ray may show an enlarged heart and fluid accumulation in the lungs or chest cavity. An accurate diagnosis of the reason behind a dog’s symptoms is necessary before it can be properly treated.

In most cases, the purpose of a CHF treatment plan is to relieve symptoms by reducing fluid buildup and improving heart function. CHF is usually progressive and can’t be cured. Treatment methods for CHF vary depending on the underlying cause and presenting symptoms. Methods for managing symptoms associated with CHF include:

• Diuretic medication to increase fluid excretion in the urine
• Heart medications to improve the way the heart functions
• Manual drainage of excess fluid
• Surgery to correct heart defects

Patients in distress may need to be stabilized in a hospital before long-term treatment can be recommended. In some cases, patients may be referred to a veterinary cardiologist for diagnostics and treatment. Dogs with CHF often need frequent, close monitoring by a veterinarian. The prognosis for dogs with heart failure is variable depending on the severity of the disease when diagnosed and its underlying cause, with some cases being immediately life-threatening. Many dogs live several months to a year with a good quality of life after diagnosis. However, as the disease progresses, the medications eventually stop helping. At this point, treatment focuses on end-of-life care and may include humane euthanasia.

Is congestive heart failure an emergency?

“CHF is often a life-threatening emergency at the time of diagnosis because that’s when symptoms become obvious,” explains Dr. Jo Myers, a veterinarian on Vetster. “The medications used to treat CHF typically provide significant relief, at least for a while, but as the disease progresses an affected dog may decompensate and suddenly develop severe symptoms.” CHF is more likely to present as an emergency following heavy exercise or when traveling to a higher elevation than the dog is used to.

CHF can produce emergency symptoms, such as:

• Difficulty breathing
• Blue gums
• Collapse
• Loss of consciousness

Symptoms can occur with untreated CHF, CHF that is being properly treated, and acute CHF. Dogs presenting with these symptoms need immediate veterinary care.

It’s important to talk to a veterinarian any time you notice symptoms such as:

• Coughing
• Reduced ability to exercise
• Lethargy

Many health conditions can cause these symptoms, so a definitive diagnosis is necessary to know what kind of treatment will work. Seek emergency care right away if your dog is having difficulty breathing, has blue lips or gums, or has collapsed. If you’re unsure if your dog is having an emergency, virtual triage with an online vet is an excellent way to get the information you need to decide the best course of action.

How do you treat heart failure in dogs?

Treatment for congestive heart failure in dogs usually involves symptomatic care rather than reversing the damage done to the heart. Symptomatic care often involves reducing fluid accumulation in the chest and/or abdomen and improving heart function with medication, manual fluid removal, and surgery in cases of congenital defects.

What is the final stage of congestive heart failure in dogs?

End-stage congestive heart failure occurs when supportive medications no longer help, leading to breathing difficulty from the accumulation of fluid and the inability of the heart to pump oxygenated blood. Treatment for dogs with end-stage heart failure involves palliative care, and humane euthanasia may be recommended.

What are the first signs of congestive heart failure in dogs?

Early signs of congestive heart failure in dogs are often subtle and difficult to detect. Depending on the underlying cause, severity, and what part of the heart is affected, signs can include a cough, rapid breathing at rest, a swollen abdomen, and a decreased ability to exercise.