Hemangiosarcoma, a malignant tumor, is one of two forms of visceral vascular tumors. The other is benign hemangiomas. Both tumors may be characterized as big blood blisters. But what exactly are visceral vascular tumors, and how does hemangiosarcoma, which is the malignant form of the tumor, affect dogs?

According to NCBI research Visceral vascular tumors may be defined as tumors that may develop in the blood vessels of a body’s internal organs, most often in the spleen, heart, or liver. Usually, it is the spleen that is most affected by such tumors in a dog. Like what was mentioned earlier, the malignant form of visceral vascular tumor is Hemangiosarcoma (HSA). And if your dog has this form of tumor, it may spread to different areas of the body if not treated quickly.

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  1. What Is Hemangiosarcoma in Dogs
  2. Symptoms of Hemangiosarcoma in Dogs
  3. Causes of Hemangiosarcoma in Dogs
  4. Treatment of Hemangiosarcoma in Dogs
  5. How Can the Emergency Fund Help with Treatment
  6. Conclusion

What Is Hemangiosarcoma in Dogs

Hemangiosarcoma (HSA) is a malignant and aggressive tumor that may develop in the blood vessels of cells. This type of cancer mostly affects middle-aged to older dogs, and large dog breeds such as Golden Retrievers, German Shepherds, and Labrador Retrievers are known to be more predisposed to it.

Being vascular, cancer may also develop in any area of the dog's body, but the spleen is more susceptible to its formation. Other areas that are commonly affected include the heart, liver, bladder, kidneys, muscles, and cutaneous and subcutaneous tissues.

Below are the most common hemangiosarcoma tumors:

Splenic: The most common hemangiosarcoma tumor, this affects your dog’s spleen. When diagnosed, two-thirds of the tumors are cancerous. Oftentimes, this type of tumor is also seen in conjunction with cardiac or liver hemangiosarcoma.

Cardiac: This normally forms in the heart’s right atrium. This is the second-most common type of hemangiosarcoma and also the most common cancer that affects the heart.

Cutaneous/subcutaneous: This affects the skin and the area under the skin.

Because Hemangiosarcoma (HSA) is aggressive, it has a high probability of spreading and causing early metastasis, affecting other tissues in a dog's body. It is not yet known what causes HSA.

Symptoms of Hemangiosarcoma in Dogs

According to UF Health research the symptoms of hemangiosarcoma depend on which areas of the body are affected. But since the type of tumor involves blood vessels that may be prone to rupturing, the clinical signs are usually associated with hemorrhage. These signs include:

Those with tumors in the heart’s right atrium may show signs of:

  • Muffled heart sounds;
  • Arrhythmias;
  • Heart failure signs;
  • Sudden death (in cases when the tumor ruptures in a vital organ or when there is severe blood loss).

For those with cutaneous, subcutaneous, or muscle tumors, symptoms may include:

  • Lameness;
  • Swelling in the affected muscle;
  • Edema in the affected area.

Having a pet camera such as the Pet Camera may help detect such symptoms early on. Because tumors like Hemangiosarcoma are malignant and aggressive in nature, detecting them early may go a long way when it comes to their prognosis.

Monitoring your dog for any signs that are out of the ordinary is important so you can address any issues before they become serious, so the Petcube Cam may be a good investment to help you with that.

Causes of Hemangiosarcoma in Dogs

There are no known causes of hemangiosarcoma in dogs yet. However, there are a few links that are worth mentioning. For example, a genetic predisposition may be likely, as evidenced by dog breeds that appear to be more prone to getting the tumor.

External factors may also play a role in its formation. Cutaneous or subcutaneous (skin) hemangiosarcoma, for example, shows UV ray exposure to be a link, especially with dogs that have light-colored and thin coats. With human hemangiosarcoma, certain chemicals, toxins, radiation, and insecticides have been associated with the development of the tumor. While studies haven’t been made with dogs, it is believed that these may also cause hemangiosarcoma in dogs and other animals.

Treatment of Hemangiosarcoma in Dogs

For most cases of hemangiosarcomas, surgery remains the primary treatment method. After surgery, chemotherapy and radiation therapy are usually recommended. This may increase a dog’s quality of life after a diagnosis. Long-term assurance of the tumors not coming back, however, isn’t guaranteed. In some cases, where the tumors have spread to organs like the heart, for example, surgery may not be practical. Limited studies have been made to assess biologics or immunotherapy in HSA.

Certain medications and procedures may also help reduce the symptoms, side effects, and complications related to hemangiosarcoma. **These include: **

  • Medications to help stop bleeding;
  • Antiarrhythmic medications;
  • Removal of fluid around the chest, heart, and abdomen;
  • Bioactive extracts sourced from mushrooms;
  • Blood transfusions.

How Can the Emergency Fund Help with Treatment

Hemangiosarcoma may cause pet emergencies, given the nature of the disease. Because of this, having a Pet Emergency Fund allows you to focus on your health and well-being without worrying about the expenses involved. Finding out that your dog has a potentially life-threatening condition is not easy, but having a Pet Emergency Fund lessens the load since you can focus more on providing the best care for your dog.


Because hemangiosarcoma is a malignant and aggressive tumor that may quickly metastasize, early diagnosis and treatment are best for a better prognosis. While there are no known causes, there have been links between genetic and environmental factors in the development of the disease.

Upon noticing any signs and symptoms, it’s best to consult with your veterinarian to determine the cause and how you can address it to improve your dog’s quality of life.

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