Hemangiosarcoma in Dogs

mt.-carmel animal hospital hemangiosarcoma in dogs

In this article, Mount Carmel Animal Hospital explains in detail the significance of hemangiosarcoma in dogs.

Hemangiosarcoma is a relatively prevalent type of cancer in dogs, accounting for approximately 5-7% of all tumors seen in dogs. In this article, Mount Carmel Animal Hospital explains in detail the significance of hemangiosarcoma in dogs.

What Is It?

Hemangiosarcoma is a highly malignant cancer that arises from cells that typically develop blood vessels. It is most prevalently found in the spleen, but also commonly impacts the liver, skin, and heart. Exposure to sunlight can trigger skin tumors or hemangiosarcoma in dogs, particularly in thinly-haired parts, including the inner thighs, belly, and eyelids. Although any breed can be affected, hemangiosarcoma more predominantly affects golden retrievers, German shepherds, and Labrador retrievers.

Clinical Signs of Hemangiosarcoma

Clinical signs of hemangiosarcoma in dogs depend on the location of the disease. For internal tumors, symptoms vary depending on the severity of any internal bleeding that may happen secondary to tumor rupture. Symptoms may be as subtle as mild lethargy or weakness with low interest in exercise or appetite or as severe as collapse, with or without a distended abdomen, pale gums, or severe respiratory signs.

Superficial skin tumors usually appear red to purple or as bumps that might bruise or bleed randomly. Tumors can develop under the skin and present as palpable soft or firm swelling. Unfortunately, it is impossible to distinguish whether a skin mass is malignant or benign from appearance or feel alone.


It is typically difficult to analyze using fine needle aspirate cytology because tumors are prone to bleeding, resulting in non-diagnostic samples. A comprehensive assessment is accomplished with additional diagnostics such as X-rays, abdominal ultrasound, and CT scans. They also analyze the extent of disease within the animal’s body. A veterinarian might recommend an echocardiogram (ultrasound of the heart) to assess the heart for the presence of a mass.

Regardless of the location or other diagnostic tests, a biopsy is the best way to diagnose hemangiosarcoma in dogs. The only way to obtain a sample for a biopsy is to perform surgery. A histopathology is necessary to confirm the diagnosis of hemangiosarcoma in dogs. Additional biopsies of other tissue may be done to examine for the presence of metastasis.


Complete surgical excision is the best treatment for hemangiosarcoma in dogs. This may also be the only alternative treatment option for certain tumors. Chemotherapy to delay the progression of the metastatic disease is recommended for sites with high rates of spread: liver, bone, spleen, heart, and tumors beneath the skin or muscle.

For patients with evidence of metastasis during diagnosis or for animals where surgical removal of the tumor is not possible, chemotherapy might be ideal to slow the progression. Alternatively, palliative therapy is best when surgical removal is not an option.


Mount Carmel Animal Hospital has been serving the Northern Baltimore/Southern York community for over 30 years and is proud to be an independently operated, small animal practice committed to excellence in veterinary medicine and client service. From grooming to wellness services, along with Canine Life Skills Training Courses, and surgical procedures, we have the expertise that will best serve the needs of you and your pet. Contact us at 410-343-0200 and follow us on Facebook!

This entry was posted on Friday, December 15th, 2023 at 12:00 pm. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.