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ACCC Oncologist Explains Blood Cancers in Dogs

Ashlyn Williams, DVM, Practice Limited to Oncology, Presents Webinar to Primary Care Vets on Hemangiosarcoma 

Hemangiosarcoma (HSA), a malignant tumor of the cells that line blood vessels, was the topic of ACCC’s Summer Webinar offered to primary care vets across Florida and the country. ACCC’s own Ashlyn Williams, DVM, Practice Limited to Oncology, delivered the presentation and provided insights valuable to dog owners who want to learn more about this type of cancer, including its causes, treatment options, and promising emerging discoveries.

To enjoy her full session, simply click here to view the recording

Overview of the disease:

Dr. Williams explained that this form of cancer is often highly malignant but depends on how the disease presents itself and where it is located. Although research into this cancer’s behavior is ongoing, it is believed that the cancer cells are located in the lining of blood vessels and interfere with the formation of new blood cells, causing tumors, tissue blood leaks, or clots. This type of cancer acts similarly to angiosarcoma in humans.

There are two types of hemangiosarcoma, visceral (located within an internal organ, such as the liver, bladder, kidneys, or even the heart) or cutaneous (located under the skin). Visceral hemangiosarcoma is discovered most often in larger breeds, such as German Shepherds, Boxers, Golden Retrievers, and Labrador Retrievers. Dogs with lighter fur, such as Pitbulls, Greyhounds, Beagles, and Boxers, may be more susceptible to cutaneous malignancies. (Note to pet owners: Pet sunscreen is an important step in preventing damage caused by ultraviolet light.)


Determining the stage of the disease is critical in determining the proper treatment and prognosis, explained Dr. Williams. Plus, she said, “a lot depends on the location of the cancer.”

For example, if the tumor has not yet ruptured, it can often be removed with surgery and have a more favorable outcome with the addition of chemotherapy. Whereas a ruptured tumor or presence in the lymph nodes and other tissues may be more challenging to battle and have a more guarded prognosis. 

The use of X-rays and ultrasounds is valuable in identifying the extent of the disease and helping veterinarians and pet owners determine the best path forward together.  Although new screening tests are now available, including liquid biopsies, traditional screening tests remain vital, stressed Dr. Williams.

Hope for the Future:

Dr. Williams noted several new studies offering promising new treatments and diagnostics for the future, including a Cornell University study regarding the use of genetic markers to achieve a more rapid diagnosis.  “When clients are forced to decide quickly without much information, tests like these may be very useful,” she said.

She also noted that receiving very specific insight from pathology reports can lead to more pinpointing of the cancer type, and, as a result, determining the best possible treatment protocol. Primary care veterinarians play a valuable role in helping their clients review those initial reports. 

Treatment options:

When tumor removal is available, taking out enough of the surrounding margins as well can help to reduce the reoccurrence of the cancer, explained Dr. Williams. If surgery is not an option, then radiation therapy can help to extend the pet’s life.  Chemotherapy, despite the cardiotoxicity in some larger dogs, remains an effective treatment option. She spoke extensively about the types of chemotherapy available and the value of combining methods to boost survival rates.  


Emphasizing once again the importance of staging and the individual circumstances of each pet, Dr. Williams expressed hope for the future. “Lots of research is being done to come up with better diagnostics, screenings, and treatments,” she said. “With every case and every study, we learn more about how to tackle animal cancer.  I’m hopeful about the future.”