This diagram shows the close relationship the stomach has with the spleen. This is important from a surgical aspect. During spleen removal, it is important to spare the large vessels which also feed the stomach. The spleen is a nonessential organ and may be removed. It acts as a filter of the blood removing dead or diseased cells as well as blood parasites. Therefore, while not essential, removal of the spleen may open the pet to certain diseases. Spleen removal or splenectomy may be performed when the spleen has potential cancer. The most common spleen cancer is hemangiosarcoma (blood vessel wall tumor). Hemangiosarcoma is common in older large breed dogs (German shepherds and golden retrievers for example). The dog often presents with acute profound weakness and loss of appetite, which is attributable to blood loss from the tumor of the spleen.
Another reason for spleen removal is “bloat”. Bloat occurs in large breed dogs when the stomach rotates and fills with gas. The gaseous distention can occur within a matter of minutes and be so severe as to cause rapid death. This rotation of the stomach can cause loss of blood supply to the spleen, necessitating removal during the emergency surgery for the bloat.