The most common splenic tumor in dogs is hemangiosarcoma. This is a very serious splenic tumor in dogs and can be life-threatening if not diagnosed and treated early. This splenic tumor starts off as a small cancerous mass and spreads quickly over the liver, heart, and lungs. Learn more about this deadly disease by reading our blog article below.

What is a splenic tumor in dogs?

A splenic tumor in dogs originates from the blood vessels of the spleen. As the spleen is made up of a large matrix of blood vessels, splenic tumors can become large very quickly due to their large blood supply. Hemangiosarcoma is a very aggressive and malignant splenic cancer in dogs that originates from blood vessels. Other common locations for a hemangiosarcoma to develop are the liver, heart, and skin but because hemangiosarcoma is a cancer of blood vessels, the mass can form anywhere in the body.

What is the prevalence of hemangiosarcoma in dogs?

Hemangiosarcoma accounts for about 5% of all primary malignancies in dogs, and it is the most common splenic tumor in dogs. Hemangiosarcoma typically occurs in middle-aged to older dogs, although it can also develop in young animals. The disease occurs most often in large-breed dogs, but small to medium-sized breeds can also be affected. Common breeds to develop hemangiosarcoma include the German shepherd, golden retrievers, and labrador retrievers.

Symptoms of splenic tumors in dogs

Hemangiosarcoma is a very serious splenic tumor in dogs and can be life-threatening if not diagnosed and treated early. The first noticeable symptom of this disease is typically a swollen abdomen. As cancer progresses, the dog may start to exhibit signs of weight loss, lethargy, and poor appetite. Hemangiosarcoma can also cause anemia, which can lead to weakness and collapse. If you notice any of these symptoms in your dog, it is important to bring them to your veterinarian for a check-up as soon as possible. In summary, clinical signs to watch out for that may be suggestive of a splenic tumor in dogs include:

As splenic hemangiosarcoma can metastasize to the lungs rapidly, there may also be additional clinical signs such as coughing, difficulty breathing, and exercise intolerance.

How is a splenic tumor in dogs diagnosed?

If your veterinarian suspects that your dog may have a splenic tumor, they will likely order some imaging tests to help make a diagnosis. Ultrasound is the most common type of imaging used to diagnose splenic tumors. A splenic mass will appear as a well-defined, round, or oval-shaped mass on ultrasound. Abdominal X-rays can also be useful since the spleen is quite apparent on survey abdominal radiographs and masses are often visible. Your veterinarian may also recommend a chest x-ray to check for any spread of the tumor to the lungs. Once a splenic mass is identified on imaging, your dog will likely need to undergo surgery to remove the mass. A biopsy of the mass will also be performed to determine the type of tumor and whether it is benign or malignant.

How is a splenic tumor in dogs treated?

The most common treatment for splenic tumors in dogs is surgery. The goal of surgery is to remove the entire tumor and this is often achieved by performing a splenectomy or surgical removal of the spleen. The spleen is an accessory organ and there are no health consequences in removing the spleen.

It is important that prior to surgery, chest X-rays should be performed. If there is evidence of metastatic lung disease, surgery should be reconsidered as metastatic lung disease is a poor prognostic indicator.

Chemotherapy may be recommended after surgery to remove a splenic hemangiosarcoma because this type of cancer often spreads quickly. The most common chemotherapy treatments include doxorubicin, either as a single drug or in combination with other drugs.

What is the prognosis of a splenic tumor in dogs?

If the post-surgical biopsy reveals the splenic mass is benign and is not hemangiosarcoma, the prognosis is very good. The prognosis however of hemangiosarcoma in dogs is very poor. Studies have shown that the 1-year survival rate is <10% and death is typically secondary to cancer spread or metastasis.

What causes splenic cancer in dogs?

Given the strong breed connections in dogs, genetic factors may play a role in the development of hemangiosarcoma. Older dogs and certain breeds such as golden retrievers, German shepherds, and Labrador retrievers have an increased risk of developing hemangiosarcoma.

Is splenic cancer painful for dogs?

The spleen is located in the upper left part of the abdomen and splenic cancer typically doesn't cause pain as it grows. Tumors can grow quite large before causing any noticeable clinical signs. It is only when the tumor ruptures or starts to bleed that dogs may show signs of abdominal pain.

How can I prevent splenic cancer in my dog?

There is no known prevention for splenic cancer in dogs. However, since the risk factors for developing splenic cancers include being an older dog and belonging to a certain breed, regular health check-ups are important so that any potential tumors can be detected early. If your dog does develop a splenic tumor, prompt diagnosis and treatment are essential for the best possible outcome.

Splenic tumors in dogs, specifically hemangiosarcoma, are serious diseases that can be life-threatening if not treated early. The first symptom of the disease is typically a swollen abdomen, followed by weight loss, lethargy, and poor appetite. If you notice any of these symptoms in your dog, bring them to your veterinarian for a check-up. Surgery is the most common treatment for splenic tumors in dogs, but if the mass has spread to the lungs, chemotherapy may also be recommended. The prognosis of splenic hemangiosarcoma is unfortunately very poor.