Hemangiosarcoma (HSA) in dogs is a highly malignant cancer of the blood vessel cells with no single known trigger, though it is strongly driven by genetic predispositions, particularly in breeds like Golden Retrievers and German Shepherds. While the exact cause is often unknown, environmental factors, chronic inflammation, and sun exposure (specifically for skin-based HSA) are likely contributors.

Why are so many dogs getting hemangiosarcoma?

Like many forms of cancer, the exact cause of HSA is unknown. Genetics likely contribute since HSA is more common in certain breeds, such as German Shepherds, Golden Retrievers and Labrador Retrievers.

Is there anything you can do to prevent hemangiosarcoma in dogs?

There are no known methods for prevention of hemangiosarcoma. Altering lifestyle behaviors, eliminating exposure to toys or other factors in the environment, and/or feeding special diets have no effect on the risk of developing this disease.

How does a dog get hemangiosarcoma?

In most cases, the cause of hemangiosarcoma is unknown. Exposure to sunlight can cause skin tumors in some dogs, especially in thinly haired regions including the belly, inner thighs, and eyelids.

Are dogs in pain with hemangiosarcoma?

The disease is indolent; in other words, it does not cause pain and the rate of growth in the early stages is relatively slow. Dogs harboring even large hemangiosarcomas may show no clinical signs or evidence that they have a life threatening disease.

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Has a dog ever beaten hemangiosarcoma?

Chase is a feisty, cream-colored dachshund owned by Krista Dieckamp, a Morris Animal Foundation donor. Chase didn't just beat the odds, though, she exceeded all expectations. Many dogs with visceral hemangiosarcoma (affecting the heart, lungs and spleen) don't survive the high-risk surgery needed to save their lives.

What is the 2/3 2/3 rule for hemangiosarcoma?

The "double two-thirds rule" for canine splenic masses suggests 2/3 are malignant, and 2/3 of those are hemangiosarcoma (HSA), meaning about 43% of all splenic masses are HSA, with the rest being benign (like hematomas) or other cancers. However, recent studies refine this: dogs with ruptured splenic masses and abdominal bleeding (hemoperitoneum) have a much higher likelihood (around 73-80%) of malignancy, predominantly HSA, requiring urgent splenectomy, while incidental masses have a higher chance of being benign.
 

What are the end stages of hemangiosarcoma in dogs?

The end stages of hemangiosarcoma are usually related to blood loss, in which case you will see signs of shock and weakness or complications from metastasis. Without treatment, dogs have days to weeks to live with visceral or heart hemangiosarcoma.

Does Benadryl shrink mast cell tumors in dogs?

Some vets use Benadryl (diphenhydramine) to blunt histamine release in mast cell tumors, and Tagamet (cimetidine) to reduce stomach acid and potential ulcer risk. This combo may ease symptoms, but it's not a cancer cure and evidence for anti-tumor effects is limited.

Is exercise good for dogs with hemangiosarcoma?

Tumors Affecting the Heart (Chemodectoma, Hemangiosarcoma)

This can result in significant exercise intolerance, therefore, over-exercise or strenuous activity may predispose pets with heart-based masses to heart-related complications.

Is death from hemangiosarcoma painful?

Hemangiosarcoma is a cancer that does not cause pain or discomfort.

Which dog breeds are prone to hemangiosarcoma?

Hemangiosarcoma (HSA) (blood vessel cancer) is most common in large breeds, particularly Golden Retrievers, German Shepherds, and Labrador Retrievers, with other predisposed breeds including Portuguese Water Dogs, Bernese Mountain Dogs, Flat-Coated Retrievers, and Boxers, though any dog can develop it, often affecting middle-aged to older dogs.
 

Can hemangiosarcoma spread to the brain in dogs?

A retrospective analysis of 85 dogs with hemangiosarcoma (HSA) that underwent complete necropsy, including gross examination of the brain, was conducted. Grossly identifiable intracranial lesions were present in 17 dogs. Twelve of 85 dogs (14.2%) had brain metastases.

What's the longest a dog has lived with hemangiosarcoma?

We report a case of a 6.5-year-old dog diagnosed with a splenic hemangiosarcoma and treated solely with micronized fenofibrate, administered orally once a day following splenectomy. The dog survived for over 26 months (804 days) after initial diagnosis without signs of adverse effects due to fenofibrate treatment.

How to tell if hemangiosarcoma has spread?

Advanced imaging, such as a CT scan or MRI, can help figure out the extent of disease spread. Veterinarians may diagnose a dog with splenic hemangiosarcoma after an acute collapse episode or weakness after a tumor ruptures.

Do dogs with hemangiosarcoma feel pain?

Unfortunately, no clinical signs (symptoms) are classic for hemangiosarcoma other than sudden, profound internal bleeding. Because this cancer doesn't cause significant pain until a rupture occurs, few dogs show any sign of discomfort.

How long does it take for hemangiosarcoma to metastasize?

Surgery is the primary method of treatment for most dogs with hemangiosarcoma, regardless of the location of the primary tumor. In most of these patients, the cancer will spread to other sites throughout the body 1-3 months after surgery. Chemotherapy delivered after surgery may delay metastasis.

What does dog poop look like with internal bleeding?

Black, tarry stool (melena) – a sign of internal bleeding in the stomach or small intestine. Bright red blood in stool or from the rectum. Profuse, watery diarrhea – especially if it's explosive or continuous.

What food causes internal bleeding in dogs?

Onions and Garlic

Even a small portion can cause stomach upset, and large amounts can actually damage your dog's red blood cells, making them rupture.

Why did my dog bleed when she died?

Sometimes, particularly in cases of congestive heart failure, chest bleeding due to a ruptured tumor, pneumonia or trauma, blood tinted fluid or sometimes frank blood can escape the nasal cavity or mouth.

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