4 Common Causes of Heart Failure in Dogs Diseases That Damage the Bodyโ€™s Most Vital Organ

BY | December 06 | COMMENTS PUBLISHED BY
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Heart failure isn't something that just happens overnight. It is possible to try to prevent this serious condition by proactively taking your dog to the vet for routine checkups. Learn more about the most common causes of heart failure in dogs.

Heart failure is a life-threatening condition that is the result of a weakened heart muscle. When the heart muscle is weakened, it is unable to provide adequate circulation, and fluid buildup can occur, most notably in the lungs. But what causes the heart muscle to weaken? Read on to learn the 4 most common causes of heart failure in dogs.

1. Degenerative Valve Disease

Degenerative Valve Disease — Also known as chronic valvular disease, endocardiosis, valvular regurgitation, or valvular insufficiency, is the most common cause of heart failure. It accounts for approximately 75 percent of cardiovascular disease in dogs. It is most common in toy and small breeds and is characterized by the degeneration of cardiac valves.

With this condition, the mitral and tricuspid valves are usually affected. The valve leaflets thicken and become deformed, and the free edges of the valves can no longer connect. These and other changes to the cardiac valves can cause them to leak, which allows blood to flow backward into the atrium of the heart. This regurgitation increases the blood pressure in the atrium and causes enlargement of the heart.

The greatest indication of degenerative valve disease is a loud heart murmur. Heart failure caused by degenerative valve disease will also likely cause coughing, rapid breathing, shortness of breath, fainting, lethargy, lack of appetite, and weight loss.

2. Dilated Cardiomyopathy

Dilated Cardiomyopathy — or DCM — is an acquired disease of the heart muscle. With DCM, the muscles of the lower heart chambers are no longer able to contract normally. Since the muscles cannot effectively pump blood out of the heart, blood will begin to back up within the heart and within the pulmonary veins that are connected to the heart. This results in an enlargement of the heart.

DCM is most common in large and giant breed dogs, especially males. Predisposed breeds include Doberman PinschersDalmatians, Great DanesBoxersNewfoundlandsCocker Spaniels, and Portuguese Water Dogs, and the specific cause of DCM can vary depending on the breed.

The symptoms of heart failure associated with dilated cardiomyopathy include loss of appetite, pale gums, coughing, difficulty breathing, increased heart rate, weakness, and fainting. A swollen abdomen may also be seen in some cases. Theophylline for dogs can help with breathing issues. 

3. Congenital Heart Disease

Congenital heart disease is caused by heart defects that have been present since birth. Common defects include valve narrowing, valve malformations, abnormal openings between heart chambers, and patent ductus arteriosus. It is a condition in which the ductus arteriosus — a blood vessel — does not close, and Tetralogy of Fallot, is an abnormality that results in insufficiently oxygenated blood being pumped into the body.

The majority of dogs with congenital heart disease die within the first year. Those who survive are likely to show symptoms such as stunted growth, difficulty with exercise, and fainting. With these dogs, heart failure can occur suddenly and without warning.

4. Heartworm Disease

Heartworm disease is caused by parasites that are transmitted via a bite from a mosquito. The arteries that carry blood from the heart become plugged up with worms, and the heart has to pump hard against the pressure of the obstruction. This is what is referred to as pulmonary hypertension, and some hearts may be strong enough to handle it, and some may not. Your vet might recommend Benazepril for hypertension. 

If worms begin backing up into the heart from the arteries, the heart will have to work even harder because there will be less space in the pumping chamber for blood. In many cases, the heart just can’t keep up, and heart failure will occur.

Heart failure can happen when the heart muscles thicken due to overwork and arrhythmia (abnormal heart rhythm) develops, which is why it is important to be aware of the options for a dog heartworm med. It can also happen when the heart muscles become too weak to function, resulting in the accumulation of fluid in the chest and abdominal cavities. In these cases, the dog may exhibit difficulty breathing and/or the appearance of a pot belly. As always, heartworm prevention is the best option. However, Drontal plus for dogs and Heartgard plus are good options when it comes to heartworm medicine.

Heart Disease Symptoms in Dogs

The main sign of dog heart failure is coughing, which is often accompanied by difficulty breathing. Your dog may also experience weakness and extreme fatigue when they exercise or move around due to reduced blood flow to their muscles. These symptoms can also be caused by other diseases that impact blood flow, such as pneumonia or anemia—it's important to consult with a veterinarian so they can perform tests that will rule out any other problems. Previcox can help temporarily with muscle pain. On the other hand, Cefpodoxime for dogs, Cefpodoxime Proxetil, and Cephalexin for dogs can be used to deal with a lung infection. 

Another common symptom is an abnormal heart rhythm called arrhythmia—this happens when your pet’s heartbeat becomes irregular or slow (bradycardia). This condition is usually caused by damage to the electrical conduction system in the heart muscle cells. If left untreated, it could lead to sudden death from ventricular fibrillation (VF). VF occurs when an arrhythmia causes an irregular heartbeat that leads to a form of cardiac arrest called ventricular tachycardia (VT).

Heart failure is not as scary as it sounds

Heart failure is not a death sentence. It’s a chronic condition that worsens over time and can shorten your dog’s life, but there is no cure for heart failure. You may also hear it called congestive heart failure (CHF), but this term is outdated. Heart failure isn't an immediate condition. It usually develops gradually over weeks or months and gets worse over time. Salmon oil for dogs and Nordic Naturals Omega 3 are well-researched supplements that can help strengthen the heart. 

The first thing to understand about heart disease in dogs is that there are many different causes of CHF, ranging from sudden traumatic events like severe blood loss or poisoning to more long-term causes like gradual buildup of fat deposits. This happens inside the arteries leading to the heart muscle itself. So while we often use vague terms like “heart disease” or “heart failure" when discussing these conditions, it's important to remember that these diseases exist on a spectrum ranging from milder forms with few symptoms to more severe cases where immediate intervention would be necessary for survival.

Prevention and Treatment of Heart Failure in Dogs

The best way to prevent heart failure is to treat the underlying cause before it progresses. A yearly visit to the veterinarian helps to ensure that problems are identified before they become severe.

If your dog does develop heart failure, it is typically treated with medication, like Vetmedin for dogs, and changes to diet. Medications can improve overall heart function and help prevent fluid buildup. Switching to a low-sodium diet can also keep fluid from accumulating.

Your dog’s chances of survival will ultimately depend on its specific condition and how quickly treatment is sought.

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