The essentials
- It’s not rare — There are many possible underlying causes of congestive heart failure which can affect dogs of any age, although the risk increases with age.
- It’s a chronic condition — While there is no cure, many dogs with congestive heart failure can live good-quality lives for months to years.
- Catching it early is important — Symptoms can be hard to spot in the early stages, but a timely diagnosis is crucial.
The term congestive heart failure can itself be scary, but understanding how it occurs and what the signs and symptoms are can empower you to secure early intervention for your pup.
What is congestive heart failure (CHF)?
Congestive heart failure (also called CHF) is the medical term for when the heart is unable to pump enough blood to the body. This leads to a backup of blood in the lungs or other parts of the body, causing fluid accumulation and various symptoms. Both humans and animals—including our dogs—can develop CHF, and it’s not uncommon. According to Pet Health Network, approximately 10 percent of all dogs (and 75% of elderly dogs) have some form of heart disease. CHF is a condition that results from heart disease, and it can cause major health issues for your pup.
There are two types of congestive heart failure: right-sided CHF and left-sided CHF.
Right-sided CHF
This happens when the heart is unable to effectively pump blood to the lungs for oxygenation. It causes blood to back up in the vessels returning blood to the heart, resulting in fluid leakage into surrounding tissues. This can cause a build-up of fluid in your dog’s limbs (medically known as peripheral edema), as well as a build-up of fluid in your dog’s abdomen (medically known as ascites).
Left-sided CHF
This is the more common type of CHF. Basically, the left side of the heart (which receives oxygen-rich blood from the lungs and pumps it to the body) gets overwhelmed, causing fluid to leak into the tissue of the lungs. This can cause coughing and difficulty breathing (medically known as pulmonary edema).
Four stages of congestive heart failure
The symptoms of congestive heart failure can vary depending on the underlying cause, which part of the heart is affected, and the severity of disease. There are four stages of canine heart disease, which can also be applied to congestive heart failure:
Stage A
During this stage, your dog is simply at risk for developing heart disease or CHF. They have no symptoms of disease and their heart is structurally normal.
Stage B
During this stage, you probably won’t be able to tell if your pet has CHF as there will be no symptoms present. However, a vet may notice something during a checkup, such as hearing a heart murmur when listening to your dog’s chest with their stethoscope. If a heart murmur is the only abnormality, a dog is said to be in stage B1. If there are also structural changes to the heart (such as enlargement) evident on X-rays or ultrasound, they are considered stage B2.
Stage C
At this stage of the disease, symptoms will be present and your dog should be receiving veterinary treatments. Early symptoms may include:
- Persistent coughing
- Tiring out more easily (exercise intolerance)
- Increased respiratory rate
- Pacing or restlessness
- Difficulty settling down
As the disease progresses, your dog’s symptoms will worsen and breathing may become harder. They may experience:
- Difficulty breathing, including wheezing and blue-tinged gums
- Loss of appetite and weight loss
- Distended abdomen or swollen limbs
- Fainting or collapse
Stage D
This is the final stage of CHF, where you may notice alarming symptoms as stated in Stage C that are no longer responding to routine treatments.
If you notice that your dog is exhibiting unusual symptoms, it’s best to get it checked by a vet.
👉 The earlier you catch CHF, the better your dog’s outlook is regarding treatment options and quality of life.
Causes of congestive heart failure
A number of different factors can contribute to your dog developing CHF over the course of their lifetime. The two most common are mitral valve insufficiency and dilated cardiomyopathy.
Mitral valve insufficiency
Located on the left side of the heart, the mitral valve sits between the left atrium (upper chamber) and the left ventricle (lower chamber). Sometimes this valve can degenerate, due to either genetic causes or other conditions.. When this happens, the leaking mitral valve will allow blood to move backward into the left atrium creating a heart murmur. As this insufficiency grows, it can increase the heart’s workload, eventually leading to CHF in some cases. This condition is extremely common, especially in older small breed dogs.
Dilated cardiomyopathy
This disease begins with a degeneration of the heart muscle causing it to become weak and thin, primarily affecting the left ventricle. When a heart is weakened by muscle loss, it can’t pump as efficiently, leading blood to pool within the heart chambers. That pressure can push at the walls of the heart giving it a stretched, dilated appearance. Murmurs and abnormal heart rhythm can follow. In certain large-breed dogs, this is a common cause of heart failure.
Dr. Liza CahnIn practice, the most common cause of CHF that I see is mitral valve disease. This condition is especially common in small-breed dogs over the age of 8.
Some breeds can be predisposed to CHF
Small breeds are more likely to develop congestive heart failure due to mitral valve disease, specifically toy Poodles, Pomeranians, Dachshunds, and Cavalier King Charles Spaniels. But some large and giant breeds are also prone to dilated cardiomyopathy, including Doberman Pinschers, Boxers, and Great Danes.
Of course, just because your dog isn’t one of these breeds doesn’t mean that they can’t or won’t develop heart disease, but owners of these breeds of dogs should keep a special eye out for the warning signs, especially if you have an older dog.
Other causes of CHF
Congestive heart failure can result from any underlying disease affecting the heart. This may be something your pup is born with (congenital) or occur later in life (acquired). .
- Patent ductus arteriosus. This heart defect occurs when a vessel connecting the pulmonary artery to the aorta doesn’t close after birth.
- Mitral valve dysplasia. When not formed properly, the mitral valve can allow blood to flow the wrong way.
- Hernias. One forming between the abdomen and the membrane around the heart during development can allow for CHF to form.
- Aortic stenosis. A narrowed aorta causes blood flow out of the heart to be dysregulated, leading to a thickening of the left ventricle which can contribute to the development of CHF.
- Heartworms. These parasites can block heart valves or even an entire heart chamber, causing the heart muscle to thicken, enlarge,and cause other serious damage.
- Parvovirus. This highly contagious virus is (thankfully) preventable with a vaccine, but if your dog catches it, it could potentially affect the heart muscles.
- Bacterial infections. Bacteria that get into the bloodstream can cause swelling in the lining of the heart or heart valves.
- Nutritional deficiency. A good diet and regular exercise are incredibly important to a dog’s overall health. Poor nutrition over the course of your dog’s life can cause CHF or potentially make CHF worse when caused by other factors. Some recent studies have shown that there’s a connection between grain-free diets and a rise in heart disease in dogs.
How veterinarians diagnose CHF
A vet visit to diagnose congestive heart failure is different from a typical check-up because special diagnostic tests are required.
First, your vet will perform a thorough physical exam and listen to your dog’s heart and lungs. Next, they may run a number of tests (listed below). In many cases, you may be referred to a cardiologist.
- Blood and urine tests. Dogs with heart diseases frequently also have liver and kidney problems, so testing blood and urine for those issues can help when deciding what medications are safe to use for your dog.
- Chest x-rays. An X-ray will help the vet see the size and shape of the heart, as well as any abnormalities in their lungs (such as fluid build-up).
- Electrocardiogram. You may hear this called an EKG; this test can detect any issues with your dog’s heart rate and rhythm.
- Ultrasound. Your vet may call this an echocardiogram. This test gives the vet a look at the shape, size, and movement of your dog’s heart. It can also help your vet figure out if your pup’s heart is pumping blood like it should be, and what medications would be best to help slow down the progression of CHF in your dog. This will likely need to be performed by a cardiologist.
- Heartworm antigen test. Because heartworms are a possible cause of CHF, your vet will probably run a heartworm test.
Without running these tests, your vet won’t be able to fully determine the stage or underlying cause of CHF, which is important for tailoring a treatment plan. The cost for these types of tests can vary and may cost less if you have insurance, but dog owners should expect to spend $500-$1000.
How to treat heart disease and CHF in dogs
Unfortunately, there is no cure for CHF. But it is a manageable health issue, especially when caught early. Your vet will put your dog on a treatment plan that is specifically catered to them, depending on the severity and underlying cause. Your vet or cardiologist may recommend a combination of the following medications:
ACE inhibitors
Common angiotensin-converting enzyme (ACE) inhibitors are enalapril, benazepril, and captopril. These prescription medications can help reduce blood pressure and improve heart function, which can relieve stress to the heart while helping slow the progression of CHF.
Diuretics
Diuretics get the kidneys going, which can help get rid of fluid buildup in the lungs and belly. They will cause your dog to have to pee much more than usual, as it pulls fluid out of your dog’s body. Make sure to take them outside as often as you can, give them access to a fenced-in area, or provide them with pee pads. This medication is often referred to as a “water pill,” and will cause your dog to require more water intake as they lose fluids by urinating, so make sure to provide plenty of fresh water.
Positive inotropes
These drugs, such as pimobendan (Vetmedin) increase the force of your dog’s heartbeats to help increase blood flow to the lungs and body.
Vasodilators
These types of medications can help relax blood vessels, which decreases pressure on the heart.
There is no cure for CHF, and once it begins, the average lifespan for a dog is anywhere from 6 months to upwards of 24 months. But early intervention and management with lifestyle and diet changes as well as medication, can positively impact your dog’s prognosis.
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Frequently asked questions
How long do dogs live when they have congestive heart failure?
Generally speaking, dogs with CHF can live anywhere from 6 months to 2 years following their diagnosis.
What to do for a dog with congestive heart failure?
The best thing you can do is consult with their vet on a proper treatment and management plan.
Is heart failure painful for dogs?
While we can’t speak to our furry friends, outward signs indicate that they don’t display obvious signs of pain, but discomfort and distress is very likely.
How do you comfort a dog with congestive heart failure?
Dealing with CHF can be difficult for your dog, but one of the best ways to comfort them is to keep to their treatment plan and shower them with all the love and support you can.
Are dog heart attacks painful?
Heart attacks are rare in dogs, but yes. Symptoms can include limping, whining, loss of consciousness, labored breathing, anxiety, and extreme lethargy. If you see your dog exhibiting any unusual symptoms seek veterinary care immediately.
