Hemangiosarcoma is a cancerous mass that is fed by the red blood cells of a dog's spleen. If not removed, the spleen will bleed spontaneously when the cancerous mass bursts, which may result in death from blood loss. Once the spleen is removed, the dog has a chance of surviving from a few weeks to a few months. Chemotherapy treatment may be able to prolong the dog's life for up to six months.
The spleen is located in a dog’s body just below the stomach and is used to give the body a fresh supply of blood by removing old red blood cells. The body is able to survive without a spleen, however, the spleen is very helpful in renewing the blood supply to the body.
Splenic Tumors in a Dog
The spleen may develop masses or tumors which can be either malignant or benign. In dogs, these masses are typically hemangiosarcomas that grow from the red blood cells of the body. The growth may eventually rupture causing the spleen to bleed which can be life threatening due to the blood loss. If not removed, the spleen will continue to bleed again and again.
If the enlargement of the spleen is due to cancer, it will develop in the blood vessels of the spleen and can quickly spread through the blood to other parts of the body. Over 75% of splenic masses are caused by cancer.
Signs of a Splenic Bleed
Signs of a splenic bleed due to a mass or tumor include a sudden show of weakness and fatigue, the dog feeling cold, and pale gums. Once the spleen stops bleeding, the dog will quickly recover.
Removal of the Spleen
The first step a veterinarian will most likely take is to remove the spleen. If the spleen is not removed, the dog will eventually die from excessive blood loss. It is typically not possible to know whether the tumor is cancerous or not without removal of the spleen. Typically, 25% of dogs with splenic hemangiosarcoma also have a heart hemangiosarcoma.
Chemotherapy for Dogs
Chemotherapy may be given to the dog after the spleen has been removed. Studies have shown that chemotherapy after surgery has improved the survival rate of dogs suffering from splenic cancer.
Chemotherapy may have side effects including vomiting, anorexia, lethargy, fever, and diarrhea. One out of 16 dogs that were studied died from complications of the chemotherapy.
Chemotherapy may be able to extend the life of the dog up to six months after surgery, according to the University of Missouri-Columbia Scott Endowed Program in Veterinary Oncology.
Prognosis for Canine Splenic Cancer
Prognosis for a dog suffering from cancer of the spleen is approximately 19 – 65 days with surgical removal alone. The use of chemotherapy may have the ability to extend that survival time for the dog up to six months.
Despite the removal of the spleen and the tumor, the dog will most likely eventually succumb to cancer.