The very term, “congestive heart failure (CHF),” is enough to make you sit up and listen. It sounds dangerous and, although there can be effective treatments, it is an illness that you need to take very seriously.
The earlier you spot the signs of CHF and act on them the better. Find out more about this potentially life-threatening and life-shortening disease as we examine the common causes and what you need to be looking out for.
Congestive Heart Failure Explained
CHF refers to the heart’s inability to pump sufficient blood from the heart to the rest of the body. Estimates suggest that around 80 percent of canine CHF cases are due to issues of the mitral value: the value between the two chambers of the left side heart. The most common of these is called myxomatous mitral valve disease (MMVD).
When a damaged heart struggles to pump, it can lead to high blood pressure in the lungs and elsewhere. This can result in fluid accumulating in the abdomen, chest or both, according to the kind of CHF.
A dog’s heart has a left and right side, as in humans. It’s the role of the left side to pump the oxygen-rich blood back out to the body to replenish the tissues. The right side has the job of taking in oxygen-poor blood from the body and transporting it to the lungs where it receives oxygen.
Although problems can relate to the right side, left-sided CHF is much more common in dogs. In both instances, excess blood leaks (flowing the wrong way) through valves causing a range of issues. These can include:
- Coughing and breathing difficulties
- Swelling of the limbs
- A malfunction of other organs
We don’t know the cause of mitral valve disease, but there does appear to be a strong genetic component. Many small breeds of dogs have a genetic predisposition to suffer from mitral valve disease as a cause of congestive heart failure.
Other Related Causes
There are lots of other but less common reasons a dog may suffer from CHF. Heart rhythm irregularities or a narrowing of the major blood vessels could also be the problem.
In larger breeds of dogs, we refer to the most common inherited type of heart disease dilated cardiomyopathy (DCM). Its characteristic is a heart muscle that becomes weak and is unable to contract correctly. This can cause the heart to dilate. Examples of dogs predisposed to DCM include Great Danes, Doberman Pinschers and Boxers.
Common Clinical Signs of CHF
The most typical clinical sign of congestive heart failure (CHF) is coughing, breathing difficulties and exercise intolerance. These signs are generally due simply to the heart needing to work harder to perform its normal functions. In severe cases, signs are due to the build-up of fluid in the lungs, known as pulmonary edema.
The enlarged heart may also push against the airways that lead to the lungs, causing irritation which can lead to coughing. Many dogs with CHF will tire more easily. You might also notice a reduction in their stamina, and they may not want to play or walk as much as they once did.
What can be particularly noticeable is that any coughing persists even when a dog is resting or asleep. Dogs with CHF may also:
- Pant excessively and lose their appetite
- Display a swollen belly, bluish or grayish gums or experience weight loss
- Suffer from fainting episodes
- Lose significant muscle mass
Dogs with a higher risk for developing CHF may initially show no symptoms or structural changes to the heart. Breeds with a genetic risk include some larger dogs such as Dobermans and Great Danes along with smaller pets like Cocker Spaniels, Miniature Poodles and some Terriers.
You should always contact an emergency vet if your dog is experiencing any signs of respiratory distress or problems breathing. Your dog may need urgent care when experiencing moderate to severe signs of congestive heart failure.
You should make yourself familiar with locations for emergency care where you live in case your dog needs urgent attention outside of regular veterinary hours.
How Your Vet Will Reach a CHF Diagnosis
There are a range of methods available that can help vets reach a diagnosis of CHF. These include:
1. Listening to the Heart
Your vet will use a stethoscope for this. It’s the first, simple step to diagnosing heart disease. They’ll be able to detect any heart murmurs along with their location and intensity.
They’ll also assess your dog’s heart rhythm. If there are concerns, they’ll examine by touching the heart area at the same time and feeling your dog’s pulse.
2. Chest X-Rays, Blood and Urine Tests
Your vet may decide to take chest x-rays so that they can take a look at the size and shape of the heart. It’s also a useful way for them to check the lungs for changes such as the presence of fluid.
They may combine these with blood and urine tests. These can indicate if there are other disorders in the body that could interact with any heart problems. Liver and kidney function, for example, can suffer as a result of heart disease.
3. An Electrocardiogram (ECG)
An ECG measures the electrical activity of the heart, helping to accurately determine the heart rate and rhythm. An ECG can help evaluating any abnormal rhythms.
4. An Ultrasound Examination
An echocardiogram or ultrasound exam uses sound waves to evaluate the heart. They can give an accurate indication of the size and thickness of each heart chamber. It’s also possible to observe the heart’s contractions to help ensure the heart is pumping efficiently. This is the gold-standard in heart examinations, but requires particular veterinary expertise.
Treatments for CHF
Treatment tends to include dealing with the underlying heart disease as well as the accumulation of fluid in the lungs.
The most typical treatment for common CHFs is the use of certain diuretics such as furosemide. Diuretics reduce the volume of the blood itself, which makes it easier for the heart to pump the blood around the body.
Your vet may also prescribe a range of other drugs to work alongside these types of diuretics. They will help with the continued management of the illness.
In extreme cases treatment may include an operation to close a vascular malformation or a repair to a leaking mitral valve. These procedures are expensive and may also not be the most appropriate type of treatment.
Monitoring CHF and the General Outlook
Monitoring your pet’s Sleeping Respiratory Rate is key with nearly all types of CHF. As long as the rate when sleeping is in the normal range (see below), it’s reasonable to assume there is adequate to good control of the disease.
As a general rule, a dog at should have a sleeping respiratory rate of fewer than 30 breaths per minute. You should count the “in” and “out” as one breath. Make sure your dog sleeping when you count, as this keeps the recording consistent.
You shouldn’t count the respiratory rate straight after physical activity. If the sleeping respiratory rate begins to increase, adjustments to treatment may be necessary. Your vet will be able to advise you about the options available.
The prognosis for a dog with CHF will depend on these factors:
- The cause of the disease
- How long the disease has taken hold
- The quality of the treatment
- The progression of the disease specific to each animal
Left-sided congestive heart failure is incurable but manageable if caught early. You will need to restrict your dog’s activity levels to ease pressure on the heart. Your vet will be able to advise you on a reasonable exercise routine.
You should only feed your dog a moderately sodium-restricted diet that is high in nutrients. You may need to change to a highly sodium-restricted diet and choose other dietary options if the disease gets worse.
Dogs with left-sided heart failure, or those with significant fluid in the lungs, may not be able to get enough oxygen from their lungs into their bloodstream. In these cases, a dog may benefit from oxygen supplementation in the short-term.
Your vet may recommend placing your dog in an oxygen cage or providing them with more oxygen through a nasal tube.
Get in Touch With Us Now
If you notice any worrying signs that might make you think your dog is suffering from CHF, your first port of call should be a vet.
We know that it can sometimes be difficult to get reassurance straightaway. That’s why we always have a qualified vet on hand to help and advise you.
Speak to one our vets right now. We also have a range of highly competitive pet insurance options.