Congestive Heart Failure in Dogs: Signs, Treatment and Life Expectancy

Signs of Congestive Heart Failure in Dogs

Left-sided heart failure (fluid in the lungs) is the most common type. Signs include:^1,3,12

• Fast or labored breathing while resting or asleep
• Coughing, often worse at night or when lying down
• Tiring quickly, lagging on walks or refusing to walk
• Restlessness at night, pacing, or sleeping sitting up
• Fainting, especially with excitement or exercise

Right-sided heart failure causes fluid to build up in the belly (a swollen, pot-bellied look) and sometimes the chest or legs.^1,3

Other signs include a poor appetite, weight loss and muscle wasting along the back and hips.¹³ See dog heart disease symptoms.

What Causes Heart Failure in Dogs?

• Mitral valve disease: the most common cause, especially in small breeds such as Cavaliers, Chihuahuas and Poodles.^4,3
• Dilated cardiomyopathy: a weak, enlarged heart muscle, mainly in large breeds such as Dobermans, Boxers and Great Danes.^14,3
• Heartworm disease, which can cause right-sided heart failure.¹⁵
• Congenital heart defects such as PDA in young dogs.¹⁶
• Pericardial effusion, where fluid around the heart squeezes it; a swollen belly is the most common sign.¹⁷
• Arrhythmias, which can trigger or worsen heart failure.¹⁸

See heart disease in dogs for more on each type.

How Vets Diagnose Heart Failure

Your vet will listen to the heart and lungs, then usually take chest X-rays, which show fluid in the lungs and an enlarged heart.⁴ An echocardiogram shows the cause and how severe it is.⁴ An NT-proBNP blood test can help: a normal result in a coughing or breathless dog strongly suggests heart failure isn't the cause.⁴ Blood tests also check the kidneys and electrolytes before and during treatment.⁴

Treatment of Congestive Heart Failure in Dogs

Dogs in severe distress may need hospital care with oxygen and injectable medication.⁴ Long-term treatment for heart failure from valve disease usually includes:⁴

• A diuretic such as furosemide (Lasix) or torsemide to remove fluid from the lungs. Expect more drinking and urination; don't limit water.
• Pimobendan (Vetmedin), which strengthens heart contractions and widens blood vessels.
• An ACE inhibitor such as enalapril or benazepril.
• Spironolactone, often added because it blocks the hormone aldosterone, which helps protect the heart.

Doses are adjusted over time, and dogs whose heart failure becomes hard to control (Stage D) may need extra or different drugs.⁴ Never change doses or stop a heart medication without your vet. See dog heart medicine.

Monitoring Your Dog's Breathing Rate at Home

Counting your dog's sleeping breathing rate is the single most useful thing you can do. A rising rate is often the earliest sign that heart failure is starting or getting worse.^4,7

1. Wait until your dog is asleep or resting quietly and not panting, in a comfortable room.⁵
2. Count each rise and fall of the chest as one breath for 30 seconds, then double it.⁵
3. Write it down every day or two so you know your dog's normal.

Most healthy dogs and most dogs with well-controlled heart failure breathe fewer than 30 times a minute while asleep.^8,7 Call your vet if the rate is consistently above 30 or clearly higher than your dog's usual; go right away if it's above 30 and your dog is also working hard to breathe.^7,5

Diet and Exercise for Dogs With Heart Failure

• Lower sodium: once heart failure develops, a lower-sodium diet is usually recommended. Avoid salty treats, deli meats, cheese and table scraps.^13,1
• Keep your dog eating: muscle loss is very common in heart failure. Your vet may suggest a heart diet, but a dog that eats is better than one that refuses a "perfect" food.¹³
• Gentle exercise: short, calm walks are usually fine. Avoid exhausting activity such as ball chasing, swimming and hot, humid days, and stop if your dog breathes hard, lags or sits down.¹²

How Long Can a Dog Live With Congestive Heart Failure?

Survival varies a lot, and vets avoid firm predictions.¹¹ The AKC cites a range of about 6 months to 1.5 or 2 years after diagnosis.³ In the QUEST trial, half of the dogs on pimobendan had reached sudden death, euthanasia for heart disease or treatment failure by about 9 months, and some lived much longer.⁹ Dogs with DCM generally do worse than dogs with valve disease.¹⁴ How well your dog responds to treatment, appetite, and how often fluid comes back are all important clues.^4,13

End-Stage Heart Failure and When to Say Goodbye

Signs that heart failure is becoming hard to control include fast breathing even on medication, coughing that keeps your dog up at night, refusing food, fainting, a swelling belly, and needing more and more diuretic.^4,1 Heart failure isn't usually painful in the way an injury is, but struggling to breathe is distressing.

Talk to your vet about your dog's quality of life: whether they can breathe comfortably, eat, rest and enjoy some daily activities. Many owners choose euthanasia when breathing can no longer be kept comfortable at home, rather than waiting for a crisis.

Frequently Asked Questions

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

Faster breathing while resting or asleep, a cough (often at night), tiring easily and restlessness at night. A sleeping breathing rate consistently over 30 a minute is an early warning.

How long can a dog live with congestive heart failure?

It varies widely. With treatment, survival ranges from a few months to about 2 years, and some dogs live longer. Dogs with DCM usually have a shorter outlook.

Are dogs in pain with congestive heart failure?

Heart failure usually isn't painful, but breathlessness and coughing are distressing. Medication adjustments can often restore comfort for a time.

What are the end stages of congestive heart failure in dogs?

Fast or labored breathing despite medication, a persistent cough, refusing food, fainting, a swollen belly and needing ever-higher diuretic doses.

Should I walk my dog with congestive heart failure?

Yes, short and gentle walks if your dog enjoys them and breathes comfortably. Stop if your dog breathes hard, lags or sits down, and avoid heat and strenuous play.

What should a dog with heart failure not eat?

Salty foods such as deli meats, cheese, chips, many treats and table scraps. Ask your vet before using supplements or changing diets.

When should I euthanize my dog with congestive heart failure?

When your dog can no longer breathe comfortably at rest, stops eating or has repeated crises despite treatment. Your vet can help you assess quality of life.

Can congestive heart failure in dogs be reversed?

The fluid can usually be cleared with treatment, but the underlying heart disease remains, so lifelong medication is needed.