When a diagnosis of an incurable disease such as heart failure or an enlarged heart is made in a dog, the owners naturally want to know what the life expectancy is with this condition. In the case of the dog with heart problems, there are also some studies on life expectancy, of which I will give a small overview below. Nevertheless, it must be emphasized at this point that each dog has an individual course and the prognosis depends on many factors.

Life expectancy in dogs with enlarged heart due to leaking heart valves

A leaky heart valve (the disease is called mitral valve endocardiosis) is the most common heart problem in dogs and affects about 75% of the entire dog population more or less badly. Small breeds of dogs are especially affected. Fortunately, not all animals ever develop symptoms. It is a progressive disease that cannot be cured. However, medications are used to try to slow the progression and manage the symptoms so that the animal has a good quality of life for a long time. More about the disease and the treatment options can be found in separate articles and in my book.

 

Mitral Valve disease in dogs

 

What is the survival time of a dog with this disease?

With water in the lungs – stage C and above

It is necessary to distinguish in the survival time whether the patient is already in heart failure. Heart failure means the dog has or had water on the lungs. From the time of heart failure, according to studies, the average survival time is about 260 days if pimobendan, furosemide (+/- ACE inhibitors, spironolactone) were used for therapy. It should be remembered that this is the average survival time and there were dogs that lived only a few days and some that lived more than 2 years.

On average, from the time of heart failure, one can assume a survival time of three quarters of a year to a year.

 

Without water in the lungs – stage B1 and B2

If the animal is not yet in heart failure, it may take years before the first symptoms of the disease appear. So it depends mainly on when the disease is diagnosed. The best way to make statements is after ultrasound monitoring has taken place several times and thus the changes can be compared over a period of time. A very large study on this has examined the effect of pimobendan (Vetmedin) on survival time or time to onset of symptoms. This involved using pimobendan as soon as the ventricles enlarged and comparing this to a placebo group. The results were astonishing. With pimobendan, the time to heart failure or cardiac death was almost 3.2 years, about 15 months longer than without pimobendan. This also shows how important it is to diagnose the disease early in order not to miss the right time to use pimobendan. If the disease is diagnosed later, e.g. when the dog develops a cough, the time to heart failure is likely to be significantly shortened, as the disease had been present unnoticed for some time and thus a large part of the 3.2 years have already passed or, as no therapy with pimobendan was given, a shorter preclinical time (approx. 2 years) must also be assumed.

The average time to heart failure from the time of cardiac enlargement with pimobendan therapy is approximately 3, 2 years without pimobendan is approximately 2 years.

 

Life expectancy in dogs with enlarged heart due to DCM

Larger breeds of dogs are more likely to develop heart muscle weakness (dilated cardiomyopathy) than valve leakage.In this case, the pumping power of the heart muscle decreases more and more.Water also accumulates in the lungs at a certain point in this disease.In addition, cardiac arrhythmias may occur.The most important therapy in the asymptomatic stage of DCM is pimobendan (Vetmedin).In a recently published study, the average life expectancy of Dobermans that were asymptomatic at the time of diagnosis was determined with and without pimobendan. Dogs with pimobendan lived significantly longer (623 days) than dogs that did not receive pimobendan (466 days).This is an important reason to diagnose the disease as early as possible. In another study of Irish Wolfhounds, the time between diagnosis and heart failure or sudden cardiac death was 65 months when they received pimobendan, compared to almost half that time with other drugs. Experience suggests that it can take between 2 and 4 years for symptoms to develop in dogs with asymptomatic DCM if it is detected early. However, there is always a risk that the animal will die of sudden cardiac death. From the time of heart failure, survival times are usually no longer than 6–12 months.

Dogs with DCM may remain asymptomatic for approximately 2–4 years.In heart failure, they often live between 6 and 12 months.

What factors affect life expectancy?

  • Additional diseases: If there is an additional disease, such as renal insufficiency, this often limits cardiac therapy and can significantly worsen prognosis.
  • Breed: Some breeds often have a faster progression of heart disease. This includes, for example, the Cavalier King Charles with mitral endocardiosis.
  • Tablet intake: Not every animal is thrilled about eating a handful of pills every day, in fact some patients hate it so much that you only get the most necessary medications in or have to resort to injections.
  • Weight loss: Especially in the late stages, cardiac patients often struggle with loss of muscle mass, which is associated with a poor prognosis.
  • Fainting spells and sudden cardiac death: If fainting spells occur, the prognosis should also be more cautious. Dogs with DCM in particular may also die quite unexpectedly from sudden cardiac death.
  • Owner behavior and response to changes: The sooner owners notice when the condition worsens, the sooner they can respond accordingly and the better the chance of stabilizing the dog again. Respiratory rate control is especially important.
References:

Effect of pimobendan or benazepril hydrochloride on survival times in dogs with congestive heart failure caused by naturally occurring myxomatous mitral valve disease: the QUEST study. 2008 Sep-Oct;22(5):1124-35. doi: 10.1111/j.1939-1676.2008.0150.x. Epub 2008 Jul 11.

Clinical efficacy of pimobendan versus benazepril for the treatment of acquired atrioventricular valvular disease in dogs. 2006 Jul-Aug;42(4):249-61.

Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study-A Randomized Clinical Trial. 2016 Nov;30(6):1765-1779. doi: 10.1111/jvim.14586. Epub 2016 Sep 28.

Efficacy of pimobendan in the prevention of congestive heart failure or sudden death in Doberman Pinschers with preclinical dilated cardiomyopathy (the PROTECT Study). 2012 Nov-Dec;26(6):1337-49. doi: 10.1111/j.1939-1676.2012.01026.x. Epub 2012 Oct 18.