Congestive Heart Failure (CHF) in Dogs

Heart disease is common in humans, and unfortunately, it’s a condition that impacts our canine friends, as well. 

Approximately 10 percent of dogs seen in a typical primary care veterinary clinic have heart disease (1). In geriatric dogs, heart disease is even more common—at least 60 percent of geriatric dogs have some degree of heart disease (2). Small- and medium-breed dogs are considered geriatric at the age of 9 years old, while large-breed dogs are considered geriatric at the age of 7. 

While some dogs with heart disease show no symptoms, some go on to develop congestive heart failure, or CHF. 

In congestive heart failure, the heart is no longer able to move blood and fluid throughout the body effectively. Dogs with heart failure experience a variety of clinical signs, including respiratory difficulties and death. 

What Is Congestive Heart Failure?

In congestive heart failure, a dog’s heart is unable to keep up with the body’s circulatory demands. The heart is responsible for pumping blood throughout a dog’s body. Failure of the heart to function properly leads to changes in circulation. Congestive heart failure causes fluid (edema) to pool in areas of the body, while also preventing oxygen delivery to the tissues.  

Congestive heart failure in dogs can be caused by any underlying heart disease. Anything that interferes with the function of the heart, causing it to work harder than it normally would, can lead to CHF.  

Stages of Canine Congestive Heart Failure

Heart failure in dogs is divided into several stages, which correspond to the severity of disease. These stages include:

Stage A: Dogs that are at risk of heart disease (due to breed predisposition or other factors) but not yet showing signs of heart disease.

Stage B: Dogs with evidence of heart disease (for example, a heart murmur) but no evidence of congestive heart failure. Stage B is further divided into two substages:

• Stage B1: There are no visible heart changes on radiographs or echocardiography.
• Stage B2: There ARE visible changes to the heart seen on radiographs or echocardiography

Stage C: This stage includes dogs with current or previous signs of heart failure.

Stage D: Dogs with ongoing signs of heart failure that are not responding to standard medical treatments

What Causes CHF in Dogs?

Congestive heart failure can be caused by any heart disease. There are no specific genetic predispositions for heart failure, but there are some dog breeds that are more likely to develop heart disease (which may progress to congestive heart failure) than others.  

Breeds that are genetically predisposed to heart disease include: 

• Beagles
• Boxers
• Cavalier King Charles Spaniels
• Cocker Spaniels
• Collies
• Dachshunds
• Doberman Pinschers
• German Shepherds
• Great Danes
• Labrador Retrievers
• Maltese
• Pomeranians
• Poodles
• Rottweilers
• Shetland Sheepdogs

Heart disease, and therefore congestive heart failure, are more common in senior dogs. Scar tissue can build up on the heart valves over time, leading to turbulent blood flow and leakage from the valves. These changes require the heart to work harder, which can contribute to CHF.

Symptoms of Congestive Heart Failure in Dogs

Signs of congestive heart failure in dogs are often subtle at first, but will progress over time. Dogs may tire quickly with exercise, breathe more rapidly than usual, and have an occasional cough. As congestive heart failure progresses, dogs typically begin to struggle more with daily activities. Breathing difficulties, decreased appetite, weight loss, and a distended abdomen (due to fluid accumulation) may be seen. 

Contact your veterinarian if you notice the following signs that may be consistent with heart failure:

• Cough
• Exercise intolerance
• Lethargy or decreased activity level 
• Increased respiratory rate while resting or sleeping
• Anorexia (loss of appetite)
• Weight loss
• Abdominal distension  

Diagnosing CHF in Dogs

The first step to diagnosing congestive heart failure is a thorough physical exam. Your veterinarian will carefully listen to your pet’s heart and lungs. Dogs in congestive heart failure typically have a heart murmur, which indicates turbulent blood flow through the heart valves. Additionally, your veterinarian may hear abnormal lung sounds called crackles, indicating the presence of fluid in the lungs. 

Other exam findings may include an increased heart rate, increased respiratory rate, arrhythmia (irregular heart beat), abnormally distended jugular veins, and the presence of fluid in the abdomen. 

The most important test for diagnosing heart failure is chest radiographs (X-rays). On radiographs, the presence of an enlarged heart and visible fluid accumulation in the lungs indicates congestive heart failure in dogs.  

Additional testing is often recommended after diagnosing a dog with congestive heart failure. 

Echocardiography, or an ultrasound of the heart, can provide valuable information about the underlying cause of heart failure. Bloodwork, including a complete blood cell count and serum biochemistry, is also frequently recommended before starting medications.

How to Treat Congestive Heart Failure in Dogs

Veterinarians are typically unable to repair the underlying cause of congestive heart failure. So, treatment focuses on managing the disease, not curing it. Patients typically require lifelong medication to control signs of congestive heart failure. 

The treatment of congestive heart failure can vary widely, depending on the dog’s condition at the time of diagnosis. Dogs with only mild signs may be treated on an outpatient basis with oral medications. These medications are designed to improve the heart’s function, aid circulation, and remove excess fluid from the body. 

In many cases, however, heart failure is diagnosed when a dog comes to the veterinarian in crisis. These dogs may require oxygen therapy, provided via a face mask or by placing the dog in an oxygen chamber. In an emergency setting, congestive heart failure is typically treated with injectable medications, including diuretics, sedatives, and other medications as needed. 

Medications for Dogs With Congestive Heart Failure

Medications used to treat CHF in dogs include:

Furosemide: This diuretic acts on the kidneys to promote the elimination of water, removing fluid that has pooled in the lungs and elsewhere in the body. Successful treatment requires carefully balancing the need to remove excess fluid with the need to prevent dehydration. 

Pimobendan: This oral medication improves heart function by improving contractions within the heart (helping the heart beat more strongly) and dilating blood vessels (allowing blood to flow through the body more easily). 

Enalapril: This oral medication helps to dilate blood vessels and slows the progression of heart enlargement. 

Pimobendan, enalapril, and furosemide are available as FDA approved drugs, and, when appropriate for your dog as determined by your veterinarian, compounded forms. If you have trouble giving your dog capsules or tablets, these medications may be available in alternate dose forms, such as soft chews or oral liquids, that can be made by a compounding pharmacy for easier administration.

In emergency situations, additional drugs may also be used. However, most dogs are treated and maintained long-term on a combination of furosemide, pimobendan, and enalapril. 

General Cost of Treatment for Congestive Heart Failure in Dogs

Cost of treatment for CHF in dogs can vary considerably, depending on the severity of clinical signs. 

In a dog with mild or subtle clinical signs, costs typically include:

• Initial diagnostic testing (radiographs, bloodwork, echocardiogram): $1,000-$1,500
• Monthly medications: $50-$150/month 
• Long-term monitoring (exams, bloodwork, radiographs): $500-$1,000/year 

In a dog that sees a veterinarian in crisis, costs may be higher:

• Initial diagnostic testing (radiographs, bloodwork, echocardiogram): $1,000-$1,500
• Hospitalization/stabilization: $1,000-$3,000
• Monthly medications: $50-$150/month 
• Long-term monitoring (exams, bloodwork, radiographs): $500-$1,000/year  

Prognosis for Dogs with Congestive Heart Failure

Many dogs with congestive heart failure do well with medical treatment, surviving to a normal life expectancy. In general, early diagnosis appears to lead to better outcomes. 

A 2018 study found that even dogs presenting with advanced heart failure (heart failure that recurred even after appropriate medical therapy) survived an average of approximately one year with changes in their treatment, with some dogs living nearly three years (3). 

How to Prevent CHF in Dogs

While most cases of heart disease are associated with age or genetic predisposition, there are two preventable forms of heart disease—heartworm disease and diet-associated cardiomyopathy. 

Heartworms are a blood-borne parasite, spread by mosquitoes. In order to prevent heartworm disease, your dog should receive year-round heartworm prevention. There are several forms of prevention available. Talk to your veterinarian to determine which option is best for your dog. 

Diet-associated cardiomyopathy is still being researched, but one particular form of heart disease called dilated cardiomyopathy (DCM) may be connected to the food a dog is eating and possible nutritional deficiencies. Talk to your veterinarian to ensure that your dog is receiving an appropriate, well-balanced diet.

Related Conditions

• Dilated cardiomyopathy
• Mitral valve insufficiency
• Mitral regurgitation
• Subaortic stenosis
• Heart murmur
• Pulmonary edema 

Covetrus encourages the use of an FDA approved product whenever possible, within a valid veterinary-client-patient relationship (VCPR). However, we realize that in order to achieve a desired therapeutic outcome, a customized compounded preparation may be necessary. Covetrus compounding pharmacies, a fully PCAB accredited pharmacy with compliance to USP 795/797/800 standards along with a registered cGMP 503B outsourcing facility means you can be confident in the quality of every medication order.