Dilated canine cardiomyopathy - Symptoms and treatment


He sick heart of a dog requires certain care so that it maintains an adequate quality of life, in addition to having its disease controlled, so as to avoid cardiac failures that put your life at risk. Below are offered five guidelines for caring for a dog with heart problems: adequate food, avoid obesity, early diagnosis of cardiac pathology, apply veterinary treatment to work and practice moderate exercise.

1. Caring for the dog with heart problems: feeding

The variety of dog food available in the market allows to cover with broadness its different nutritional needs, including those of dogs that suffer from heart disease. High-end trademarks elaborate specific feed for dogs with heart disease which have a low salt content and an extra taurine and carnitine, animal proteins that protect the heart, as well as antioxidants or omega 3 fatty acids and B vitamins.

A dog with heart problems should exercise moderately and avoid sedentary lifestyle and obesity.

Homemade recipes with veterinary supervision They can also be an option to feed a dog with heart problems. However, this alternative requires the owners effort and perseverance to adjust to the appropriate ingredients and quantities determined by the veterinarian. This type of diet can be applied in cases of dogs that are unappetizing in front of the food dish.

The diet of a dog with heart problems should be custom, because each case is different and needs nutritional guidelines that fit their needs. In this way, a dog with cardiac pathology who is overweight needs a low-calorie diet. In the opposite case, it would be found that he suffers from chronic weight loss (cachexia), which is also characterized by muscular atrophy, fatigue and weakness. In this case, the animal needs a diet high in calories.

2. Avoid the obesity of the dog with cardiac pathologies

Being overweight is a health problem that aggravates the dog's heart problems and that can even trigger them. To avoid extra kilos, food is a fundamental ally: the right portions and a good quality feed, which may be low in calories, are the basis for avoiding overweight that affects heart health.

The dogs that suffer from heart conditions can also lose their appetite, both for the medication and for the discomfort derived from their disease. This Inapetence can be fought with juicy foods such as cans, which are more attractive to the dog's palate, but always under the supervision of a veterinarian.

3. Diagnosis of dog heart failure

Recognizing the heart condition of the dog in time is the best way to treat you early, to avoid sequelae that further deteriorate the health of your heart. Symptoms like fatigue, decay, night cough, breathing difficulties or swelling of the abdomen They are signs to go to the veterinarian as soon as possible.

Around 85% of older dogs suffer from some cardiac pathology, and with adequate treatment they have a high life expectancy

Age is a common risk factor for them to develop heart conditions. In general, all older dogs end up having heart failure. "85% of greater they suffer it, "says Juan Antonio Aguado, veterinarian.

Certain dog breeds, such as large ones (mastiff), have a greater tendency to suffer certain heart problems. Large dogs age at a faster rate than small dogs, and with seven years they can have alterations in the functioning of their heart, which can be weak. However, the small dogs They may also have other heart conditions, such as endocardiosis or degeneration of the heart valves.

4. Treatment for a heart sick dog

Once the animal has a veterinary diagnosis regarding its heart condition, it is normal for the specialist to apply a treatment, such as vasodilators or diuretics. The administration of these medications should be followed closely, as well as the guidelines indicated by the veterinarian.

"The periodic reviews of the dog with heart problems are key, especially until it is possible to adjust the treatment that keeps the animal stable," says Aguado. "A dog that suffers from heart disease and has adequate treatment significantly increases both his hope and his quality of life," says María Victoria Acha, veterinarian.

5. Moderate exercise for can with cardiac pathologies

The fact that a dog has a sick heart does not imply that he needs a sedentary life. Quite the opposite. In these cases, moderate exercise is a trick to keep the canine heart in shape.

However, "the dog that suffers from the heart must perform an amount of physical activity according to its ability," explains Aguado. So if the dog is tired during the walk, it is advisable to return home to rest, and not insist on continuing physical activity.

Causes and risk factors

The causes of this disease are unknown and that's why technically it is known as idiopathic cardiomyopathy. Idiopathic means that the causes are unknown.

However, several possible causes have been proposed, among which are:

  • Poor nutrition
  • Viral infections
  • Protozoan infections
  • Exposure to toxic substances
  • Immunological problems
  • Genetic causes

The dogs most likely to suffer from this disease are those of large and giant breeds, although some medium breeds are also very prone to suffer cardiomyopathies. The breeds that are most at risk are: former English shepherd, boxer, American cocker spaniel, English cocker spaniel, Dalmatian, Doberman, Golden Retriever, Great Dane, Afghan Hound, Scottish Hound, Irish Hound, Portuguese Water Dog, St. Bernard, Schnauzer , springer spaniel and Newfoundland.


Since the causes of the canine dilated heart disease, it is not possible to prevent it. Some breeders suggest preventing sick dogs from reproducing, assuming that cardiomyopathy could be hereditary.

This article is purely informative, at we have no power to prescribe veterinary treatments or make any kind of diagnosis. We invite you to take your pet to the veterinarian in case he presents any type of condition or discomfort.

If you want to read more articles similar to Dilated canine cardiomyopathy - Symptoms and treatment, we recommend that you enter our section of cardiovascular diseases.

Main symptoms

The increase in the size of the heart causes blood to accumulate inside, in the veins and in the lungs, causing the emergence of some signs and symptoms such as:

  • Shortness of breath that worsens over time,
  • Weakness and fatigue when making small efforts,
  • Dizziness and fainting,
  • Heart palpitations,
  • Increased blood pressure,
  • Decrease in the amount of urine produced per day.

It is important to see a doctor if these symptoms are present, since when it is not treated in time it can cause heart failure, heart attack or sudden death.

Cardiomegaly degrees

Depending on the size of the heart, cardiomegaly can be classified into 4 degrees, so the cardiothoracic index is calculated through a posteroanterior chest radiograph, where the transverse diameter of the cardiac silhouette is measured with the greater transverse diameter of the thorax and , depending on the value the degrees can be:

CardiomegalyCardiothoracic index
Grade I (Mild)0.5 to 0.55
Grade II (Moderate)0.55 to 0.60
Grade III (Moderate to Severe)0.60 to 0.65
Grade IV (Severe)> 0,65

How the treatment is performed

The treatment for cardiomegaly should be carried out under the direction of the cardiologist, and the use of diuretic medications may be recommended and to regulate the hormones that control blood pressure and heartbeat, improving the functioning of the heart. The medications normally used to treat cardiomegaly are Carvedilol, Metoprolol, Bisoprolol, Enalapril, Captopril, Ramipril, Spironolactone and Furosemide.

However, if the use of medications is not enough, it may be necessary to perform surgery to redo the cardiac structure, or if the person suffers arrhythmias, place a pacemaker and, in the most severe cases, perform a heart transplant.

Causes and diagnosis of Cardiomegaly

Cardiomegaly arises as a result of some diseases such as Chagas disease, high blood pressure, poor circulation, alterations in the heart valves and heart failure, in addition to this it can also occur due to excess alcohol and problems in the structure of heart cells .

The diagnosis of cardiomegaly is made based on the individual's medical history through examinations such as X-rays and an electrocardiogram that identifies the degree of heart failure presented by the heart.

It is important to identify the first signs and symptoms that may indicate a problem at the level of the heart, so as to go as soon as possible to the cardiologist to perform an evaluation and indicate the most appropriate treatment according to the cause, thus avoiding complications.


It is defined as a primary disease of the heart muscle of unknown etiology> Studies have revealed that of every 600 patients referred, 2 to 6 of them are diagnosed with this pathology. There are certain races in which the presentation of the disease is greater: Doberman Pinschers, Iris Wolfhound, boxer and cocker spaniel especially. The typical age of presentation is between 6 and 8 years of age although it can be seen in animals as young as 3 years (1).

It is called idiopathic when possible secondary causes have been ruled out. Numerous myocardial diseases that cause CMD include: nutritional deficiencies (taurine and L-carnitine deficiency), medication-induced cardiomyopathies (adriamycin), infectious and inflammatory cardiomyopathies, hypothyroidism and family cardiomyopathies (4,5).


The progressive degeneration and atrophy of the cardiomyocytes leads to a dysfunction in their ability to contract, so that the output of blood per minute decreases (cardiac output). Sympathetic, hormonal and renal compensatory activity stabilizes cardiac output thanks to an increase in circulating blood volume, even an increase in heart rate and an increase in blood pressure. The increase in pressure at the end of diastole caused by the increase in circulating volume leads to a dilation of the cardiac chambers. What initially compensates for cardiac dysfunction degenerates into venous congestion and ultimately congestive heart failure (1, 2). With the passage of time and in the final stages of the disease, the cardiac output ends up decreasing again, producing then a low-cost heart failure that eventually culminates with a shock of cardiogenic origin (5). Eventually the low cardiac output and the increase in diastolic pressures compromise coronary perfusion, producing myocardial hypoxia, which further worsens the function and arrhythmias are generated (2). There are individuals where the presentation of arrhythmias such as premature ventricular contractions (CVPs), or atrial fibrillation (AF) occur during the initial asymptomatic phase (2). In AF, the loss of "atrial kick" severely decreases cardiac output and may precipitate acute cardiovascular decompensations (2). We have observed some individuals mainly of the boxer race, presented to dermatological consultation due to the appearance of pyogenic follicular dermatitis that, upon exhaustive cardiovascular evaluation, show echocardiographic signs of myocardial dysfunction, which makes us think that dermatological signs are related to the decrease in perfusion dermal (personal observation).

A genetic basis is suspected in some races of high prevalence of the disease: Doberman Pinschers, Boxers and Cocker Spaniels (2,3).

Some races tend to have distinctive characteristics of the disease: Dalmatians tend to exhibit more ventricular and atrial dilation than other races. The boxers are tending to show normal cameral sizes despite the assistolic myocardial dysfunction. Dobermans tend to present less right commitment (3).

The disease usually progresses in an asymptomatic sub-clinical way to a chronic symptomatic form of congestive and low-cost heart failure. Some individuals have sudden death from severe ventricular arrhythmias without other previous clinical signs.

Asymptomatic hidden phase.

The duration of this phase is variable, it can be from months to years, and during this period there is a progressive cardiac enlargement and worsening of arrhythmias.

  • There are no obvious clinical signs but slight signs may be present in paraclinical exams:
  • Electrical conduction abnormalities such as premature ventricular contractions.
  • Increase of atrial and ventricular dimensions sonographically or radiologically.
  • Decreased myocardial contractility in cardiac ultrasound.
  • 40% of dobermans have sudden death as the first clinical sign (1).

Symptomatic phase

Clinical signs develop

  • Congestive heart failure
  • Syncopes
  • Exercise intolerance
  • Arrhythmias
  • Premature ventricular contractions
  • Ventricular tachycardia
  • Atrial fibrillation
  • Death due to advanced heart failure and refractory to treatment.
  • Between 30 to 50% of dobermans die suddenly (1)


It is the test for diagnosis of arrhythmias. May give evidence of ventricular enlargement. But a normal result does not rule out dilated cardiomyopathy. During the hidden phase, arrhythmias can be seen and in susceptible races, routine testing of this test is recommended. If the arrhythmias are permanent, it is a good diagnostic test. Not so for intermittent arrhythmias that are very common in this pathology. The detection of the following findings is very suspicious of dilated cardiomyopathy:

  • One or more premature ventricular contractions in a Boxer or Doberman.
  • Criteria for ventricular or atrial enlargement.
  • Atrial fibrillation (1,2).

The findings in a Holter are:

  • More than 100 CVP in 24 hours.
  • Between 50 and 100 CVP another test should be performed 2 to 6 months later.
  • Sometimes multiple Holter assessments are needed for diagnosis (1,2).

During the clinical phase it is common to find frequent CVPs, ventricular tachycardia, criteria for atrial or ventricular enlargement, left bundle branch blockages and atrial fibrillation:

Electrocardiography may suggest the presence of myocardial dilation, but normal data does not rule out cardiac dilation.


It is insensitive to mild cardiac enlargements, while in advanced stages of the disease it is very useful for the diagnosis of congestive heart failure. You can see distention of the pulmonary veins and interstitial or alveolar opacities, especially in the hilar and dorsocaudal areas in the left ICC. In the right insufficiency we see pleural effusion, distention of the caudal cava, hepatomegaly and ascites (2).


It is the most useful and best sensitive diagnostic tool for the diagnosis of canine and feline CMD. It is used to quantify cardiac enlargement and systolic function. Many animals in very early stages of the disease may have normal echocardiographic values ​​despite having arrhythmias. Some only show enlargement of the ventricular cavity in systole with normal diastolic dimensions. Some animals demonstrate atrial enlargement in echocardiographic evaluation before it is radiologically demonstrated (3).

The following echocardiographic data have proven to be high-risk predictors for developing CMD:

  1. LVIDd> 46 mm (dogs under 42 kg) or> 50 mm (dogs over 42 kg).
  2. LVIDs> 38 mm.
  3. CVPs during the first exam.
  4. FS 8 mm. This is the most sensitive and specific value of all (1,2,3).

With advanced disease:

  • Obvious ventricular and atrial enlargement.
  • Flattening and atrophy of the papillary muscles (2).
  • Decreased systolic movement of the septum and left ventricular wall.
  • Decrease the shortening fraction.
  • Mild to moderate mitral regurgitation.
  • Incomplete opening of the aorta.
  • Decrease in the flow rate of the aorta.
  • Increase in distance from point E of septal separation.
  • Global hypokinesis
  • Dysfunction of the mitral apparatus and atrial regurgitation (1,2,3).
  • Sometimes thrombi are observed in the atria (3).

Echocardiography is useful for the evaluation of the patient's prognosis. A restrictive trans mitral filling pattern (radius E: A greater than 2) and a shortening of the E wave deceleration time (