The spleen is an abdominal organ that normally functions as storage site for red blood cells, filtration of blood to remove old red blood cells, and for production of antibodies. A splenectomy is the surgical removal of the spleen. Splenic neoplasia (cancer) is the most common reason for performing a splenectomy. Splenic masses (benign or malignant) or trauma can cause the spleen to rupture which creates an emergency situation due to the potentially massive blood loss that occurs. The spleen may also be removed as treatment for immune mediate hemolytic anemia.

A celiotomy (abdominal exploratory) is required to perform a splenectomy. Animals can live without a spleen. The most severe complication is hemorrhage which can occur during and after a splenectomy. Your pet will be monitored in the hospital for several days following a splenectomy to monitor for blood loss and cardiac arrhythmias. Your pet should remain exercise restricted for 3 weeks following surgery to allow the abdominal muscles to heal properly.

The prognosis depends on the underlying reason for performing the splenectomy.

	Spleen after removal from the abdomen. A splenic hemangiosarcoma was diagnosed.		Splenic torsion at surgery (the spleen has twisted and the vessels are thrombosed (clotted)).

Splenic Tumors

Tumors or masses involving the spleen are the most common reason why the spleen is removed. There are both benign and malignant masses that occur in the spleen. Splenic hematoma or hyperplasia are examples of benign masses. The prognosis following removal of the spleen for these benign lesions is good.

The most common malignant splenic tumor is hemangiosarcoma. Other malignant tumors involving the spleen include leiomyosarcoma, fibrosarcoma, osteosarcoma, lymphosarcoma, and mast cell tumor which all have variable prognoses.

Splenic hemangiosarcroma is a tumor that arises within the blood vessels. It is highly malignant since it is being delivered to virtually every organ due to the blood vessels. The spleen is the most common place for this tumor to occur, but may occur in the heart, bone, or skin. Metastasis (spread) is usually found in the lungs, liver and heart. It usually occurs in older dogs (>8 years of age). It is common for these dogs to present with acute collapse due to tumor rupture leading to blood loss.

Most splenic tumors in cats are mast cell tumors.

Your pet may undergo abdominal and thoracic (chest) radiographs and an abdominal ultrasound to diagnosis a mass in the spleen. These diagnostic tests can not differentiate between a benign or malignant mass unless there is obvious signs of metastasis. A splenectomy is performed and the spleen is submitted to a pathologist for review. This is the only way to diagnose hemangiosarcoma.

The prognosis for splenic hemangiosarcoma is poor without chemotherapy. The average survival without chemotherapy is less than 3 months. The survival rate increases to 3-6 months with chemotherapy. Some dogs with or without chemotherapy have shorter or longer survivals and the above information is based on averages.