What is Hemangiosarcoma in Dogs?

While there are some cancers that are slow-progressing and easy to treat, hemangiosarcoma is not one of them. Hemangiosarcoma is a deadly form of cancer that can affect dogs of all ages and breeds, though certain breeds have a higher risk for the disease. Let’s talk about what this disease is and how it can be treated.

What is Hemangiosarcoma in Dogs?

Hemangiosarcoma is a malignant, highly metastatic form of cancer that typically begins in the liver and spleen. This form of cancer originates in the dog’s endothelium and then works its way into the blood vessels, spreading throughout the body. Many dogs develop a large mass on the liver or spleen in the early stages which can then spread to other parts of the body, even the brain or heart. There are technically three kinds of hemangiosarcoma:

• Dermal – Forming on the skin.
• Hypodermal – Forming under the skin.
• Visceral – Forming on the spleen, heart, and pericardium.

A hemangiosarcoma is actually fed by the blood vessels and as it fills with blood, there is a risk for rupture which can lead to severe hemorrhaging and even sudden death. In many cases, the dog owner doesn’t even realize that something is wrong until the hemangiosarcoma ruptures and the dog collapses. This disease can affect dogs of all breeds and ages but certain breeds seem to have a higher risk – these include English Setters, Great Danes, German Shepherds, Boxers, Golden Retrievers, and Pointers. The risk for hemangiosarcoma also seems to be higher for male dogs and the average age of onset is 8 to 10 years.

What are the Treatment Options?

The symptoms of hemangiosarcoma are usually related to the organs affected by the disease – primarily the spleen and liver. Common symptoms of impaired liver or spleen function include:

• Unexplained weight loss
• Weakness or lameness
• Intermittent and sudden collapse
• Loss of muscle coordination
• Partial loss of movement
• Seizures
• Rapid heart beat
• Fluid in the abdomen
• Acute blood loss

As is true for many forms of cancer, the cause for hemangiosarcoma in dogs is unknown. Because the cause of this condition is unknown, there is little that can be done to prevent it if your dog has a predisposition. Treatment options may vary depending on the severity of the disease and the rate of progression but most cases require inpatient care. In some cases, the tumor can be removed surgically and it may be paired with chemotherapy to lengthen the dog’s survival time, though it isn’t always effective. Some dogs may require blood transfusions to repair severe anemia and intravenous fluids to manage dehydration.

Because is a deadly and progressive disease, you may want to think carefully about how aggressively you want to treat it. If you catch the disease early you may be able to extend your dog’s life by several months with certain treatments. In other cases, however, supportive care may be the best option – you’ll need to discuss the options with your veterinarian to choose the one that is best for your dog.