Do Dogs Cough Up Phlegm With Congestive Heart Failure?

What is Congestive Heart Failure in Dogs?

Congestive heart failure (CHF) is a condition in which the heart cannot pump enough blood to meet the body’s needs. In dogs, CHF is most commonly caused by degeneration of the heart valves or by dilated cardiomyopathy, which is a disease of the heart muscle (AKC). As the condition progresses, blood backs up behind defective valves or an enlarged heart, causing fluid to build up in the lungs and abdomen. This is called congestion, which is where the term congestive heart failure comes from.

The prevalence of CHF in dogs varies by breed. For example, the cavalier King Charles spaniel is predisposed to chronic valve disease and over 50% of cavaliers aged 6 years or older are affected by CHF (Animal Care Center). Other breeds like dobermans, boxers, and cocker spaniels also have a genetic predisposition to dilated cardiomyopathy. Overall, CHF is one of the most common heart diseases in dogs.

Signs and Symptoms

Some of the most common signs and symptoms of congestive heart failure in dogs include:

Coughing – One of the hallmark symptoms of heart failure is a persistent, dry cough. Coughing is caused by the buildup of fluid in the lungs. Dogs may cough when at rest or when sleeping. The cough may worsen at night. Source

Fatigue/Weakness – Dogs with heart failure often experience a lack of energy and weakness. They may be reluctant to exercise or play. Simple daily activities like going for a walk may leave them exhausted. Dogs may also faint or collapse due to a lack of energy. Source

Difficulty Breathing – Fluid in the lungs makes breathing difficult for dogs with CHF. They may breathe rapidly or pant excessively even when at rest. Some dogs assume an open-mouth breathing posture to help get more air. Source

Fluid Accumulation – Excess fluid builds up in the lungs and abdomen due to improper pumping of blood by the heart. This is called edema. Dogs may cough up white, frothy fluid. The abdomen may become distended and swollen with fluid. Source

Is Coughing Up Phlegm a Symptom?

Coughing up phlegm or mucus is a common symptom in dogs with congestive heart failure (CHF). When a dog has CHF, fluid can build up in and around the lungs. This fluid puts pressure on the lungs and airways, causing inflammation and production of phlegm.

According to the HeartSmart Pet Hospital at Tufts University, coughing is a symptom in over 80% of dogs with heart disease or heart failure [1]. The phlegm coughed up is often white, foamy, or pink tinged.

There are two main reasons a dog with CHF may cough up phlegm:

  1. Fluid accumulation in the lungs (pulmonary edema) – Excess fluid in the lungs causes inflammation and production of phlegm. As the dog coughs, this phlegm can be coughed up.
  2. Left-sided heart failure – When the left side of the heart fails, blood backs up into the lungs. This causes damage and fluid leakage into the airways, resulting in phlegm production.

So in summary, coughing up phlegm or mucus is a very common symptom in dogs with CHF resulting from fluid buildup in the lungs. If your dog is coughing up phlegm, especially if white and foamy, see your vet as it can indicate heart disease.


A veterinarian will diagnose congestive heart failure in dogs based on the dog’s medical history, a physical exam, and diagnostic tests. On physical exam, the veterinarian will listen to the dog’s heart and lungs with a stethoscope. They may detect an abnormal heart rhythm or murmur, abnormally fast heart rate, weak pulse, coughing, or crackling/rasping sounds in the lungs. The main diagnostic tests used are:

  • Chest x-rays – These can show an enlarged heart and fluid buildup in or around the lungs.
  • Echocardiogram – An ultrasound of the heart that evaluates the heart’s size, shape, and function. It can detect issues like weakened heart muscles or leaky valves.
  • Electrocardiogram (ECG) – Records the electrical activity of the heart to detect abnormal rhythms.
  • Blood and urine tests – To check for issues like anemia, kidney disease, or thyroid problems which could contribute to heart failure.

Based on the exam and test findings, the vet can diagnose congestive heart failure and determine the underlying cause, like dilated cardiomyopathy, valvular disease, or another heart condition leading to CHF.


Treatment for congestive heart failure in dogs focuses on improving heart function, controlling fluid buildup, and managing symptoms. The main treatments include medications, dietary changes, activity management, and at-home monitoring.

Commonly prescribed medications include:[1]

  • Diuretics like furosemide help remove excess fluid from the lungs and body
  • ACE inhibitors such as enalapril relax blood vessels and decrease strain on the heart
  • Pimobendan, a positive inotrope, improves heart contraction
  • Digoxin increases the strength of the heart’s contractions

Veterinarians may adjust medication types and dosages over time to optimize treatment. Monitoring fluid buildup and being alert to side effects are important while managing medications.

Lifestyle changes can take pressure off the heart and improve quality of life. Obesity exacerbates heart failure, so vets often recommend weight loss for overweight dogs. Restricting exercise, providing soft bedding, controlling environmental temperatures, and limiting stressors helps dogs conserve energy for their weakened hearts. Low sodium diets reduce fluid retention as well.

At home care involves monitoring symptoms like coughing, breathing rate/effort, and fluid buildup. Routine vet visits allow evaluation of heart function through exams, x-rays, and bloodwork. Ongoing care aims to provide dogs comfort and quality time with their families.


The prognosis for dogs with congestive heart failure depends on several factors. With treatment, the average life expectancy is generally 6 months to 2 years from the time of diagnosis. However, some dogs can live longer with proper management of the condition.

Some of the main factors that affect prognosis include:

  • Cause of the heart failure – dogs with acquired heart disease tend to have a better prognosis than those with congenital issues.
  • Severity of the heart disease – dogs with more advanced disease and heart enlargement tend to have shorter survival times.
  • Response to treatment – dogs who respond well to medications like diuretics, ACE inhibitors, etc. tend to live longer.
  • Presence of secondary conditions – diseases like kidney failure can worsen prognosis.
  • Breed and size – smaller dogs tend to live longer than larger breeds with heart disease.
  • Age – younger dogs have better outcomes compared to senior dogs.
  • Overall health status – dogs in good physical condition otherwise can better tolerate heart medications.

With dedicated treatment and owner commitment, some dogs can live comfortably with congestive heart failure for 1-2 years or longer. Close monitoring and follow up care with a veterinarian is key to optimizing quality of life and longevity.

Living with a Dog with CHF

Caring for a dog with CHF can be challenging but rewarding. With treatment and careful management at home, dogs with CHF can continue to enjoy a good quality of life.

It’s important to follow your veterinarian’s recommendations for medications, diet, and exercise. Restricting exercise, providing easy access to food and water, and giving medications as prescribed can help manage your dog’s condition. Gentle walks and mental stimulation through games or training are usually safe activities for a dog with CHF.

Monitor your dog’s breathing and alert your vet if it seems labored. Weigh your dog regularly to check for fluid retention. Avoid overexcitement and stress. Handle your dog gently and use ramps or steps to avoid jumping on/off furniture.

Your vet may recommend supplements like taurine or coenzyme Q10. Ask about monitoring tools like blood pressure cuffs to track changes at home. Joining a support group can also help you care for your dog’s needs.

As CHF progresses, focus on quality of life. Look for signs your dog is in pain, unable to enjoy activities, or suffering more bad days than good. Your vet can help advise end of life care when your dog’s quality of life declines. With thoughtful management, dogs with CHF can still live happily.


There are several ways to help prevent congestive heart failure in dogs:

Get your dog screened early. Many vets recommend annual heart screenings for dogs over 7 years old to catch any potential issues early. An echocardiogram and chest x-rays are common diagnostic tests. Early detection allows for earlier treatment which can greatly improve outcomes.

Maintain a healthy weight. Being overweight puts extra strain on the heart. Keep your dog at an ideal weight by measuring their food, avoiding unhealthy treats, and exercising regularly.

Feed a high quality diet. Choose a dog food fortified with taurine, carnitine, omega-3 fatty acids and antioxidants. These nutrients support heart health. Consult your vet on the best diet for your breed.

Control underlying conditions. Manage diseases like hypothyroidism, diabetes, and high blood pressure which are risk factors. Follow your vet’s treatment plans for any diagnosed conditions.

Exercise moderately. Regular, gentle exercise strengthens the heart muscle and improves circulation. But avoid overexertion which can strain the heart. Low-impact activity is ideal.

Avoid toxins. Don’t expose your dog to tobacco smoke. Use flea/tick medication as directed. Limit lawn chemicals that could enter their system.

Provide excellent care. Annual vet visits allow thorough exams to monitor heart health over time. Being proactive reduces risk.

When to See a Vet

There are certain warning signs you should watch for in a dog with congestive heart failure that indicate a need for urgent veterinary care:

Emergency symptoms that require immediate veterinary attention include:
– Sudden weakness or collapse
– Labored, distressed breathing or panting at rest
– Pale gums or tongue
– Coughing up blood-tinged phlegm or froth
– No interest in food for more than a day
– Chest filled with fluid, distended abdomen
– Crying out or vocalizing from pain
(Small Door Veterinary)

If your dog is showing any of these life-threatening signs of advanced heart failure, don’t wait – get them to the emergency vet clinic right away. Time is critical when a dog’s heart is failing and immediate veterinary support is needed to try to stabilize them with medications or oxygen.

Other non-emergency but still concerning signs to have checked by a vet within 24 hours include:

– Fainting or collapsing

– Heavy, wet-sounding cough

– Extreme lethargy or trouble walking

– Loss of appetite

– Bluish gums or tongue
(VCA Hospitals)

Close monitoring and quickly addressing any progression of symptoms is crucial with congestive heart failure. Don’t delay in getting veterinary assessment, as early intervention can give dogs the best chance of staying stable and comfortable.

The Takeaway

Congestive heart failure is a serious condition in dogs where the heart is unable to pump blood effectively. This leads to fluid buildup in the lungs or chest, causing symptoms like coughing, fatigue, and breathing issues. While coughing up phlegm or foam is not a definitive symptom, it can occur in some dogs with CHF. The best way to diagnose CHF is through chest x-rays, an ECG, and an examination by a veterinarian. With early detection and proper treatment, including medications and dietary changes, many dogs can manage CHF and live happily for months or years. If your dog is showing any signs of respiratory distress, it’s crucial to get them checked by a vet right away. Prompt treatment greatly improves their outlook and quality of life. While CHF cannot be cured, dog owners have an important role to play in helping their pets stay as healthy and active as possible. Be alert to any changes in their breathing and energy levels, follow your vet’s treatment plan diligently, and cherish every moment with your beloved companion.

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