Congestive Heart Failure in Dogs: All You Should Know About It

By S G July 16, 2022 Dog Diseases, Dog Health, Heart Support, Obesity in Dogs, Supplements for Dogs 0 Comments

Congestive heart failure in dogs may be a frightening diagnosis. In most cases, it is caused by the disability of the left side of the heart to flow blood out and through the body, resulting in edema accumulation.

Edema is the presence of fluid in tissues or body cavities where it should not be. This edema most often builds in the lung tissue or chest cavity due to left-sided heart failure, making breathing difficult.

Unfortunately, many minor and some giant breeds are predisposed to acquiring this illness later in life. The good news is that this diagnosis is manageable with correct therapy and lifestyle changes.

However, detecting the signs of congestive heart failure in dogs is critical. As a result, treatment may begin as soon as possible, giving your beloved canine an excellent chance of living a longer life.

Continue reading to learn about dogs’ most frequent causes of heart failure, symptoms, tests and treatment options.

Table of content

What Is Congestive Heart Failure in Dogs?
What Is the Difference Between Right-Sided and Left-Sided CHF?
Stages of Congestive Heart Failure
Symptoms of Congestive Heart Failure in Dogs
Causes of Congestive Heart Failure in Dogs
How Veterinarians Diagnose Congestive Heart Failure in Dogs
Treatment of Congestive Heart Failure in Dogs
Recovery and Management of Canine Congestive Heart Failure
Preventing Congestive Heart Failure in Dogs
The Takeaway
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What Is Congestive Heart Failure in Dogs?

Congestive heart failure in dogs (CHF) is a condition in which fluid accumulates (congests) due to the heart’s impaired capacity to properly circulate blood throughout the body.

A diseased heart may struggle to pump blood, causing blood to back up in the lungs and, depending on the type of CHF, fluid accumulates in the chest, belly or both.

A dog’s heart has right and left sides like a human’s. The right side is in charge of receiving oxygen-depleted blood from the body and transporting it to the lungs, where it is oxygenated. The left side is in charge of returning oxygen-rich blood to the body to feed the tissues.

What Is the Difference Between Right-Sided and Left-Sided CHF?

Congestive heart failure in dogs may be classified as either right-sided or left-sided.

Left-Sided Congestive Heart Failure

In dogs, this is the most prevalent kind of congestive heart failure. The heart’s left side gathers oxygen-rich blood and pushes it to the body’s organs. If you observe a dog coughing and gagging, congestive heart failure is the most probable reason.

Trouble breathing and exercise intolerance are all symptoms of a pressure build-up in the veins carrying blood to the left atrium (upper chamber) and ventricle (lower chamber). Consequently, fluid builds up in the lungs (a condition known as pulmonary edema).

Dogs with left-sided congestive heart failure may sometimes faint due to a blood flow and oxygen shortage in the brain. That is related to the so-called sudden heart failure in dogs. These pets often breathe more quickly than healthy canines.

Right-Sided Congestive Heart Failure

The heart cannot pump enough blood to the lungs for oxygenation if the right side of the heart is weak or if a valve malfunctions. Pressure rises in the arteries that transport blood to the right atrium, veins and capillaries throughout the body.

This may result in fluid accumulation in the abdomen, a condition known as ascites. Fluid may also seep from veins in the legs, causing swelling, known as peripheral edema.

Biventricular Failure

The bilateral failure occurs when both the right and left ventricles fail to function adequately. Both types of symptoms can be observed.

Stages of Congestive Heart Failure

The risk and development of congestive heart failure in dogs are similar to how it is defined in persons with the same disease. The stages go from being at risk for CHF but not showing any symptoms (Stage A) to having severe symptoms (Stage D).

Stage A: Dogs are at a greater risk of developing CHF but have no symptoms or anatomical alterations to the heart. Small breeds such as Miniature Poodles, Cocker Spaniels, Terrier types and certainly bigger dogs such as Great Danes or Dobermans are in danger.
Stage B1: Dogs have a heart murmur (a “whooshing / swishing” sound that a veterinarian can hear but no symptoms. A murmur implies that blood flow inside the heart is disturbed.
Stage B2: Dogs with a structural alteration on an X-ray / radiograph or echocardiography (a specialist ultrasound used to assess the heart) but no symptoms.
Stage C: Heart disease symptoms are apparent at this stage. Dogs at this stage will have present or previous clinical evidence of congestive heart failure. However, they will still react well to drugs and therapy.
Stage D: That condition is often known as “end-stage” disease. At this stage, a dog will usually have severe illness symptoms that do not respond to drugs or other therapies.

Symptoms of Congestive Heart Failure in Dogs

The signs and symptoms of CHF might vary based on the underlying heart disease and whether the heart is afflicted on the right or left side. In certain circumstances, symptoms can be the same on both sides.

These warning symptoms should be taken carefully and handled with your veterinarian as soon as possible:

Fainting.
Inability to exercise.
Difficulty breathing / shortness of breath.
Fatigue.
Persistent coughing.
Lack of appetite.
Pacing before bedtime and difficulty settling down.
Weight loss.
Swollen belly (due to fluid build-up).
Increased heart rate.
Gum and / or tongue color change to a bluish-gray (a result of poor oxygen flow).
Crackling sound when listening to the lungs.

Both right-sided and left-sided congestive heart failure eventually result in tissue oxygen deprivation and heart failure.

Causes of Congestive Heart Failure in Dogs

Myxomatous mitral valve disease (MMVD), also known as chronic mitral valve disease, degenerative mitral valve disease, mitral insufficiency, or endocardiosis, is the most prevalent cause of congestive heart failure in dogs.

The mitral valve, also known as the bicuspid or left atrioventricular valve, is located on the left side of the heart and serves as a connection point between the left atrium and the left ventricle.

MMVD develops when the entryway fails to shut, allowing blood to escape through the valve. It leads to left-sided congestive heart failure over time as the left side of the heart loses its capacity to pump oxygen-rich blood to the body.

Although the origin of mitral valve disease is uncertain, there seems to be a considerable hereditary component. Many small-breed dogs are genetically predisposed to mitral valve dysfunction, which may lead to congestive heart failure.

The most frequent hereditary type of cardiac illness in large-breed dogs is dilated cardiomyopathy (DCM), which causes the heart muscle to weaken and become unable to contract adequately. The heart enlarges as a result of this. Doberman Pinschers, Boxers and Great Danes are breeds prone to DCM.

Other causes of canine CHF include:

Heart valve disease.
Congenital cardiac defects (patent ductus arteriosus, pulmonic stenosis and aortic stenosis) are the most common reason for congenital heart failure in dogs.
Defects or holes in the walls of the heart (ventricular septal defect).
Heartworm disease.
Fluid build-up in the sac surrounding the heart (pericardial effusion).
Increased blood pressure.
Arrhythmias (irregular heartbeat).
Infection (endocarditis).
Tumors (chemodectoma, lymphoma and hemangiosarcoma).

How Veterinarians Diagnose Congestive Heart Failure in Dogs

The diagnosis of congestive heart failure will begin with a stethoscope listening to the heart and lungs. Most dogs will have a cardiac murmur, which will be scored from 1 to 6.

Grade 1: A very mild murmur that is often difficult to hear.
Grade 2: Soft murmur but readily heard.
Grade 3: Moderately loud murmur.
Grade 4: Loud murmur.
Grade 5: A very loud murmur may be detected with the stethoscope while just touching the chest. Vibration may be felt through the chest wall above the heart by the vet (palpable thrill).
Grade 6: A loud murmur may be detected with a chest stethoscope (not touching the skin). Vibration may be felt through the chest wall above the heart by the vet (palpable thrill).

If your veterinarian suspects CHF, he or she will likely order a chest X-ray / radiograph. It is essential for finding signs of heart enlargement or fluid in the lungs (pulmonary edema). An electrocardiogram may also examine the heart’s pace and rhythm.

Your veterinarian may recommend you to a veterinary cardiologist for further testing, such as an echocardiogram or cardiac ultrasound. An echocardiogram is the most helpful technique for determining the source of a murmur, the probable cause of CHF and the capacity of the heart to pump blood.

Treatment of Congestive Heart Failure in Dogs

Your veterinarian will most likely advise treating both the underlying cardiac condition (if feasible) and any fluid build-up. Although an underlying cause, such as heartworm disease, may be curable, the cause of congestive heart failure cannot be cured in most instances. It can only be controlled.

Medications for CFH in Dogs

The drug used to treat canine CHF will differ based on the underlying cause and severity. Your veterinarian or cardiologist will decide on the best medications, doses and frequency and should be contacted before making any modifications.

Diuretics are often used as the basis of congestive heart failure therapy (water pills). Depending on the etiology of heart failure, they reduce fluid build-up in the lungs, belly or legs.

Pimobendan is another medicine that is often used to treat CHF. This medication enhances the heart’s capacity to contract, boosts pumping activity, opens blood arteries and minimizes the heart’s work.

Pimobendan has been demonstrated to postpone the development of heart failure. It enhances overall survival time in the treatment of myxomatous mitral valve disease and dilated cardiomyopathy when begun before symptoms occur (stages A and B CHF).

Digoxin, Diltiazem, Angiotensin-converting Enzyme (ACE) inhibitors, beta-blockers, and calcium channel blockers are some more drugs that may be beneficial in CHF. To treat your dog’s unique CHF and underlying heart disease, your veterinarian will most likely prescribe a mix of drugs.

Oxygen Therapy for CHF in Dogs

Dogs with left-sided heart failure or many fluids in the lungs may be unable to transfer enough oxygen from their lungs to their bloodstream. A dog may benefit from oxygen supplementation in such instances.

Your dog may be put in an oxygen cage or given oxygen via a nasal tube. Alternatively, direct airflow toward the face (also known as “flow by” oxygen) may be delivered.

In extreme circumstances, a dog may need to be intubated (a tube inserted down the trachea) to get oxygen or even mechanical ventilation (having a machine breathe for them). But this comes with a terrible prognosis.

Nutrition for CHF in Dogs

In addition to medicinal therapy, nutritional management and food may be employed. Nutrition suited to your dog’s underlying cardiac issue may help reduce disease progression and enhance the quality of life.

Healthy objectives, food suggestions and supplementation should constantly be reviewed with your primary veterinarian, veterinary cardiologist or veterinary nutritionist.

Specific dietary supplements such as fish oil / omega fatty acids, taurine and L-carnitine may be given. They can be used to reduce inflammation, assist with arrhythmia management and enhance cardiac function.

Other suggestions may include weight control, mass muscle maintenance and consuming a well-balanced diet. Again, before making any dietary modifications or adding supplements, contact your veterinarian, cardiologist and / or a veterinary nutritionist.

Recovery and Management of Canine Congestive Heart Failure

Your veterinarian and / or veterinary cardiologist will adapt recovery and care to your individual dog depending on the etiology of the CHF. However, most dogs can enjoy modest exercise and activity without limitations.

Monitoring the respiratory rate or the number of breaths per minute is essential for at-home treatment in patients with left-sided congestive heart failure. The respiration rate may indicate the amount of fluid in the lungs and help you decide whether you need to visit your veterinarian.

Generally, a dog at rest should have a respiratory rate of fewer than 30 breaths per minute. When counting, ensure the dog is at rest or sleeping and that you count in and out as one breath. Do not attempt to measure its respiratory rate shortly after physical exertion.

Your veterinarian will also do periodic chest X-rays to determine the heart’s size and fluid indications in the lungs.

Blood tests, including kidney values and electrolytes, will most likely be necessary every 3 – 6 months to check your pet’s cardiac medication is working correctly.

Echocardiography will most likely be rechecked by the veterinary cardiologist every 6 – 12 months to detect changes in the heart and make medication modifications as required.

Congestive heart failure in dogs is incurable. Still, your four-legged friend may have a pleasant and prolonged life with careful treatment for congestive heart failure in dogs and regular meds.

When stage D occurs, the median survival time is nine months.

Preventing Congestive Heart Failure in Dogs

To avoid CHF, owners must be aware of the signs and symptoms of heart issues and manage them as soon as possible. Proper eating is essential, but vitamins may also help avoid heart disease.

Some early research has shown a relationship between grain-free diets and heart disease (specifically dilated cardiomyopathy). If your dog is on grain-free food, consult your veterinarian about switching to a grain-containing diet.

The Takeaway

Congestive heart failure is frequent in dogs, affecting 75 percent of older canines. While there is no cure for the illness, medicines and lifestyle modifications may help manage it.

Because it is not always simple to identify in its early stages, prevention is essential. Adequate food, exercise and weight management are crucial for canine cardiovascular health.

Be aware of the signs and symptoms so you can get care as soon as you believe canine congestive heart failure is a problem and keep up with your yearly vet check-ups.

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