A Facebook post on the Animal Medical Center’s wall congratulating Dutch for being the first dog to complete a clinical trial protocol for hemangiosarcoma at AMC generated this question: “Since Dutch had his spleen removed, does he need special vaccinations going forward?” Below is my rather long answer.
The spleen is a soft, spongy, dark red organ that dangles off the stomach, connected by a thin veil of tissue and blood vessels. This organ is a component of the immune system and in some ways is just a very fancy lymph node. Like lymph nodes, the spleen is responsible for clearing infectious organisms from the body and it also participates in recycling senescent blood cells.
Because the spleen floats somewhat freely in the abdomen, attached to the stomach by thin tissue and blood vessels, splenectomy is not an intricate surgery. Through an abdominal incision, the surgeon clamps off blood vessels, ligates (sutures, staples or clips them securely closed), severs the ligated vessels and tissue, removes the spleen from the abdomen, and submits it to the lab for biopsy. Finally, the abdominal wall is closed with sutures or staples.
Need for Splenectomy
Dutch, the dog in the Facebook post, had his spleen removed because of a common, canine splenic tumor, hemangiosarcoma. Other tumors, such as mast cell tumors, lymphoma or sarcoma, are also frequent indications for splenectomy. Blunt force trauma, a fall from a height, or an automobile accident, can result in splenic rupture and lead to a splenectomy. Twisting of the stomach, also known as gastric torsion or bloat, can tear the blood vessels connecting the spleen to the stomach, and without an intact blood supply, the spleen must be removed. Because the spleen plays a role in removing aged blood cells, a malfunction of the spleen may increase blood cell destruction. To control blood disorders like immune-mediated thrombocytopenia (ITP) or some forms of hemolytic anemia, splenectomy can be part of the treatment protocol for some blood disorders.
Complications of Splenectomy
In dogs, complications of splenectomy include the typical post-operative ones like incision infections and poor healing. Depending on the underlying cause for splenectomy, blood transfusions and repair of fractures may be necessary. In dogs undergoing splenectomy for tumors, abnormal heart rhythms frequently occur and veterinarians monitor for arrhythmias in the ICU for a day or so following splenectomy. Once discharged from the hospital following splenectomy, dogs can resume normal activity once the incision is well healed.
The Facebook Question
While the indications for splenectomy sound a bit scary, the surgery itself seems straightforward in the dog. So why did AMC’s Facebook friend ask their question? Human patients undergoing splenectomy have many more long term sequelae than our canine patients. Splenectomized humans receive antibiotics prior to dental procedures, vaccinations to protect them against pneumonia and meningitis, and exercise a great deal of caution if they develop a fever. This blog often talks about One Health, the concept acknowledging the links between the health of animals, people and the environment, but in the case of splenectomy, the dog the dog stands alone.