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Heart Tumors In Dogs – Symptoms & Treatments

Heart Tumors In Dogs

What Is Heart Tumors In Dogs?

Heart or Cardiac tumors are abnormal growths in the heart muscle or heart chambers or in its adjacent structures. Heart tumors may be primary or secondary tumors (metastasis - cancer spread). The most common form of primary heart tumor is a right atrium Hemangiosarcoma and chemodectoma. The prevalence of hemangiosarcomas is approximately 10 times that of chemodectomas.

Other less common heart tumors include lymphoma, granular cell tumors, lymphosarcomas, Mesotheliomas, rhabdomyosarcomas, and fibrosarcomas.

In general, cardiac tumors in dogs are rare; the reported prevalence is 0.10% to 0.20% in dogs. Secondary heart tumors originate somewhere else in the body and then spread to the heart. While heart tumors in dogs are rare, they can cause fatal complications including pericardial effusion, arrhythmias, congestive heart failure, and obstruction of blood flow. These tumors can cause bleeding into the pericardial sac or interfere with the normal function of the heart. When normal heart function is interfered with or compromised, it will ultimately lead to heart failure.

Mostly Primary canine cardiac tumors occur in giant breeds, there is no sex predisposition and in middle-aged animals (lymphomas are an exception which seem to appear more often in older dogs). Documented cases suggest that neutering is the reason for the increase in the risk of cardiac tumors in both sexes.

Heart tumors may occur at any age and both the sexes are equally vulnerable. However, most heart tumors occur in Middle-aged dogs (average age > 5 years).

Symptoms Of Heart Tumors In Dogs

  • Heart murmur
  • Labored breathing
  • Intermittent cough
  • Exercise intolerance
  • Increased heart rate
  • Tachypnea - Rapid breathing
  • Pleural effusion - Fluid accumulation in the lungs, within the lungs (pulmonary edema), and abdomen (ascites).

Non-specific symptoms include:

  • Tiredness/Lethargy
  • Respiratory distress
  • Loss of coordination
  • Pain
  • Collapse

Treatment Options For Heart Tumors In Dogs

Recovery and survival rates are dependent on the grade and stage of the tumor as well as the promptness of the treatment.

Grade IHeart tumors:

  • Chemotherapy is generally not required.
  • Surgical removal.
  • When surgical excision is not a viable option, a combination of radiation and marginal surgical removal or radiation therapy alone are the next best options.

Grade IIheart tumors:

  • Extensive surgical excision.
  • When there is less chance of success for wide surgical excision, a combination of radiation therapy /chemotherapy’ marginal surgery will be the option.
  • Multi-centric/ Metastatic disease- Chemotherapy.

Grade III heart tumors:

  • Due to this tumor's high metastatic potential, Chemotherapy is recommended.
  • Chemotherapy drugs are used to make the best use of the effect.
  • Supplementary measures such as antacids and antihistamines are recommended.

Home Remedies For Heart Tumors In Dogs

  • Keep in mind natural remedies may not clear the problem, but they may help to reduce some of the symptoms.
  • Pain can be so subtle in dogs –access your dog’s pain and watch out for any abnormal behavior.
  • Don’t forget even with sick dogs need a few low-stress activities and a lot of rest.

Prevention Of Heart Tumors In Dogs

There are no reliable means to prevent heart disease in dogs, especially since few of the common types are inherited.

Turning on the nutritional way of life: Feed your pet a healthy diet that includes heart-healthy nutrients.

Limit exercise options: Canine cardiac health is intricately related to exercise. When your pet has been diagnosed with heart ailments, figure out correct exercise options such as walking.

Parasite preventatives: Flea and tick preventatives such as heartworm preventatives.

Carcinogenic exposure: One of the most important changes you can make is reducing carcinogenic exposure such as pesticides, secondary smoking, and other chemicals.

Industrial pollution and chemicals: Arsenic, plastic, leather, textiles, dyes. Keep your dogs away from these carcinogenic risks.

Affected Dog Breeds Of Heart Tumors

Large Dog Breeds, German Shepherd, Golden Retriever, Labrador Retriever, Middle Age Dogs, Senior Dogs, Afghan Hound, Boston Terrier, Boxer, Bulldog, English Setter, French Bulldog, Irish Water Spaniel, Saluki, Scottish Terrier

Causes And Types For Heart Tumors In Dogs

1. Causes:

The cause for the development of heart tumors is not easy to understand. Very few tumors have a single known cause. Secondary heart cancer is 40% more likely than primary cancer that originates in the heart.

  • Congenital/idiopathic
  • Immune system irregularities
  • Radiation
  • Certain viruses
  • Extreme exposure to the sun
  • Poisonous mushrooms
  • Benzene

2. Types:

  • Grade 1 – Cells are well-differentiated. Metastasis- Low, Recurrence rate- 25%.
  • Grade 2 – Averagely differentiated. Metastasis- locally invasive, Recurrence rate- 45%.
  • Grade 3– Badly differentiated. Metastasis- High potential, Recurrence rate- 75%.

3. Mortality:

  • Grade 1- negligible
  • Grade 2- 20%
  • Grade 3- 100%

This tumor's activity is based on many factors and it is complicated. Generally, the tumor is staged from 1-3; stage 1 is less fatal than stage 3 tumors. Malignancies have an increased tendency to spread when moving from 1-3.

4. Diagnosis:

  • Complete blood profile and urinalysis
  • Cardiac ultrasound
  • Echocardiography
  • Chest radiographs
  • CT scan
  • Tissue biopsy

5. Prognosis:

Typically, the prognosis will not be encouraging if:

  • The dog belongs to the susceptible bracket
  • Actively replicating cells is more (when examined through the microscope)
  • Aggressive primary canine tumors

Grade I tumors can have a good prognosis.

Grade II tumors can have a guarded prognosis.

Grade III tumors that have spread to several sites have a poor prognosis.

When To See A Vet For Heart Tumors In Dogs?

Time to visit the vet clinic for an examination, if you notice any of the following:

  • Exercise intolerance
  • Increased heart rate
  • Rapid breathing (known as “tachypnea”)

Food Suggestions For Heart Tumors In Dogs

For adult dogs the minimum dietary requirement would be:

Protein (2. 50 g of protein of high biologic value per kg) + carbs (no minimum dietary requirement) + good fats (1.5 g of fat / kg metabolic body wt/day) + (include omega-3 fatty acids and arginine).

Some of the most popular include:

  • Protein: High protein diet comprising 40% of the dog's calories.
  • Protein: Lean chicken or turkey breast, lean beef, and Cooked fish (salmon, tuna).
  • Complex Carbohydrates: Fibers and starches (Whole Grains, Oatmeal, Brown Rice, Potatoes & Sweet Potatoes).
  • Antioxidants: Blueberries, Cauliflower, Beets, Beans, etc.
  • Omega 3 fatty acid foods (Sardines, salmon, Mackerel, Herring, etc).
  • Obese dogs: Lower calorie filling foods, for underweight dogs- calorie-dense foods.


The prognosis for Heart tumors in dogs depends on the type of cancer and how early it was treated. The median (average) survival time is 2- 4 months with supportive care alone. With proper treatment, however, the survival time for dogs can be significantly increased.

Unfortunately, there is insufficient data in the veterinary literature to assess the effect of most heart tumors grade on clinical outcomes. However, higher histological grades are prone to have a poor prognosis.

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