The spleen is an organ that's job is to filter the blood and remove old red blood cells. It is also plays a role in the immune system. This article discusses some of the common diseases in dogs that require removal of the spleen (splenectomy).
Why Does My Dog Need to Have His Spleen Removed?
The most common problem in dogs that results in removal of the spleen is a tumor. Splenic tumors are often cavitated, meaning they have fluid (blood) in the center, and can grow quite large. These tumors are at risk for rupture and leakage of blood into the abdomen. Tumors on the spleen can be benign or cancerous.
If a tumor is found on the spleen but is not yet bleeding into the abdomen, the chance of the tumor being cancerous is about 50/50. Tumors that have ruptured and are bleeding into the abdomen are somewhat more likely to be cancerous. Approximately 75% of bleeding splenic tumors are cancerous. The most common cancer of the spleen is called hemangiosarcoma.
Other less common reasons why your veterinarian might recommend splenectomy include splenic torsion and splenic trauma. Splenic torsion is when the spleen twists on itself and the blood supply is compromised resulting in an enlarged, blood filled and painful spleen. Trauma to the spleen most commonly occurs if a dog is hit by a car.
What Are the Symptoms of a Splenic Tumor?
Dogs with splenic tumors can have variable symptoms. If the tumor is not actively bleeding, there may no symptoms at all. If bleeding does occur, your dog may have episodes of weakness or lethargy. In cases of severe bleeding into the abdomen from acute rupture, dogs may collapse and go into shock. Severe cases can result in death if emergency veterinary care is not reached in time.
How Are Splenic Tumors Diagnosed?
Splenic tumors can sometimes grow very large and may be felt by your veterinarian when they do a physical examination of your pet. If your veterinarian suspects a mass, radiographs (x-rays) and/or abdominal ultrasound will be recommended to visualize the mass. This will also help to determine whether fluid (blood) is present in the abdomen.
Basic bloodwork does not always show any abnormalities with splenic tumors or other cancers. If bleeding into the mass or into the abdomen is significant, there may be changes found such as low red blood cell counts or low platelets (the cells used to help clot your dog's blood).
What Is the Treatment for Splenic Tumors?
The only real treatment for splenic tumors is surgical removal of the spleen. The procedure is done under general anesthesia. An incision is made through the abdominal wall and the spleen is removed. In most cases this procedure goes smoothly and is not a high risk surgery.
However, if there is significant blood loss, the surgical risk increases, and your dog will need to be stabilized prior to surgery. Stabilization may include a blood transfusion if the bleeding is significant.
Some dogs with splenic tumors develop abnormal heart rhythms, which also can be dangerous and may require treatment.
What Is the Prognosis?
The prognosis for benign tumors is excellent and splenectomy is all that is required. Unfortunately, dogs with cancerous splenic tumors do not do as well. Even if there is no obvious metastasis (spread of the tumor) to other organs at the time of surgery, cancerous splenic tumors almost always recur after the spleen is removed. The tumor can grow again in the liver or other sites in the abdomen.
Average survival times after surgery are only a few months with hemangiosarcoma. Chemotherapy after surgery is an option and may help to extend your dog's life by another few months. Newer chemotherapy protocols may show some promise and may extend life longer. Your veterinarian can contact a veterinary oncologist to obtain the most up to date chemotherapy protocols.
Despite all of the spleens functions, dogs can live normally without their spleen. Most dogs never have a problem. There are a few infections that affect red blood cells that occur more in dogs without their spleen but the incidence is low.