Congestive heart failure is a serious condition that impacts the heart’s blood-pumping ability. When the heart isn’t working as intended, circulation can be severely disrupted, and fluid buildup can happen across the body, especially the lungs.
Key Takeaways
Congestive heart failure in dogs is a progressive and irreversible condition in which blood flow is impaired, causing fluid buildup throughout the body.
It’s generally caused by mitral valve disease, dilated cardiomyopathy, heartworm disease, congenital heart defects, arrhythmias, pericardial disease, and infections.
CHF is treated and managed with emergency care, medications, dietary management, and lifestyle adjustments.
Left-Sided vs Right-Sided CHF in Dogs
CHF in dogs is generally categorized based on which side is affected. This matters because it will determine where the fluid accumulates.
Left-Sided CHF
Left-sided congestive heart failure in dogs is generally the most common form of heart failure. This is generally caused by mitral valve disease. In this type, fluid backs up into the lungs.
Right-Sided CHF
Right-sided CHF often occurs as a consequence of left-sided CHF, heartworm disease, or tricuspid valve disease. Instead of fluid backing up into the lungs, fluid will build up in other parts of the body, usually the abdomen or body tissues.
What Are the Symptoms of Congestive Heart Failure in Dogs?
These signs often develop gradually as the heart disease progresses.
Persistent Coughing. Coughing is one of the most common signs of CHF in dogs. This becomes noticeable at night or after exercise.
Breathing Difficulties. Dogs with CHF may breathe faster or have problems with breathing, even when they rest peacefully.
Exercise Intolerance. Some dogs become tired more easily after the same amount of exercise and walking.
Lethargy and Weakness. A dog with CHF may seem unusually tired or weak. They may sleep more than usual or become reluctant to do some activity.
Reduced Appetite and Weight Loss. Loss of appetite is expected due to decreased energy levels. This may result in weight loss.
Restlessness. Some dogs may be unable to settle down at night because of discomfort with their breathing.
Fainting or Collapse. Poor oxygen circulation to the brain may result in fainting or collapse.
Distended Abdomen. Fluid buildup in the abdomen can cause a swollen or bloated appearance.
Pale or Bluish Gums. Changes in gum color can indicate poor oxygen circulation
What Are the Stages of CHF in Dogs?
Congestive heart failure in dogs may progress over time, and our vets use a staging system to describe how advanced it is.
Stage | Description | Symptoms |
|---|---|---|
A | Breeds with a high risk of developing heart disease | No symptoms present |
B1 | A heart murmur is present, but no significant heart enlargement | No symptoms present |
B2 | A heart murmur is present with heart enlargement | No symptoms present |
C | Urgent treatment and medication are required | Fatigue, coughing, lethargy, and other symptoms |
D | End-stage CHF that is difficult to manage, requiring intensive care | Severe and significant symptoms |
What Causes Congestive Heart Failure in Dogs?
Now that we know the types, symptoms, and stages, we’ll talk about what causes CHF in dogs.
Mitral Valve Disease
MVD is the most common cause of congestive heart failure in dogs, especially in toy and small dog breeds. It happens when the mitral valve weakens and is unable to close properly, making blood leak backward inside the heart.
Over time, this strain causes the heart to enlarge and eventually leads to fluid buildup in the lungs. Common breeds at risk include Cavalier King Charles Spaniels, Pomeranians, toy Poodles, and Dachshunds.
Dilated Cardiomyopathy
DCM causes congestive heart failure in dogs by weakening and thinning the heart muscle, particularly the left ventricle. This results in an impaired ability to pump blood, making blood back up into the lungs or the body.
Large and giant dog breeds are generally at higher risk, including Doberman Pinschers, Newfoundlands, Great Danes, and Boxers.
Heartworm Disease
Adult heartworms may cause a physical obstruction, blocking blood flow and making the heart work harder. This may lead to right-sided CHF in dogs.
Additionally, these parasites may cause inflammation, scarring, and thickening of the pulmonary artery walls, reducing elasticity and causing high blood pressure.
Congenital Heart Defects
Dogs with structural defects, valvular malformations, and narrowed vessels may experience increased pressure, chamber enlargement, and inefficient blood pumping. A common example is patent ductus arteriosus.
Arrhythmias
Arrhythmias disrupt the heart’s ability to pump blood effectively, resulting in reduced cardiac output, increased heart strain, and fluid accumulation. Arrhythmias can be fast, slow, or irregular.
Pericardial Disease
Pericardial disease generally causes right-sided CHF in dogs, primarily through pericardial effusion. This results in cardiac tamponade, which is when the buildup of fluid creates high pressure, causing blood to back up into the body.
Infections
Certain infections may also contribute to heart disease and congestive heart failure in dogs. Common ones include bacterial endocarditis, leptospirosis, canine parvovirus, and canine distemper
It’s important to understand that CHF itself is not a disease, as it’s the end result of underlying heart problems that have progressed over time. These conditions weaken the heart’s ability to function properly.
CHF is a progressive condition, which means that it will worsen over time if not managed well. However, early diagnosis and treatment significantly help dogs live for months or even years with a good quality of life.
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