WHY MIGHT THE SPLEEN NEED TO BE REMOVED?
There are several reasons why the spleen might need to come out. In dogs, by far the main reason is a growth or mass on the spleen which has broken open and started bleeding and much of the discussion below regards this scenario. Other reasons to remove the spleen involve curtailing the pitting function reviewed above. In immune-mediated anemia, the spleen is removing too many red blood cells and the patient is suffering for it. Usually medication is used to suppress the immune-system but sometimes this is inadequate and the spleen must come out. Similarly, animals being considered as blood donors sometimes have their spleens removed to curtail the pitting function and facilitate the detection of blood parasites that might preclude use as a blood donor.
Additional reasons to remove the spleen include infiltration by cancer. In particular, there is a form of mast cell cancer in cats which is largely limited to the spleen and removing the spleen can be provide a long remission or even cure. Sometimes the spleen is ruptured in a trauma and must be removed to control the bleeding. For the most part, spleens are removed because they have grown a mass which has started to bleed so our discussion will begin here.
SPLENIC MASSES – WHY ARE THEY BAD?
Occasionally spleens grow masses. These are generally either benign tumors (hemangiomas) or malignant tumors (hemangiosarcomas grow from the red pulp, mast cell tumors and lymphosarcoma arise from the white pulp.) In dogs, most splenic masses are either hemangiomas or hemangiosarcomas while in the cat they are usually either mast cell tumors or lymphosarcomas.
Since we are concerning ourselves with the dog today, we will review the hemangioma and hemangiosarcoma. Both these tumors arise from the blood vessels of the red pulp and amount to a bunch of wildly proliferating abnormal blood vessels. Eventually the growth ruptures and the spleen bleeds. When a vascular organ like the spleen bleeds, a life-threatening blood loss can result.
Unfortunately, the splenic mass is certain to bleed again and if the spleen is not removed, eventually the patient will bleed to death.
If the splenic tumor is benign, removing the spleen is curative provided that the patient has not lost too much blood to survive the surgery. Ideally, the splenic mass is detected before it has ever bled and the spleen is removed at a time when the mass is not actively bleeding. Of course, if the splenic mass IS actively bleeding and cannot be stopped with pressure wraps, removing the spleen becomes an emergency surgery; it is not appropriate to try to wait until the bleeding has stopped.
If the splenic tumor is a malignant hemangiosarcoma, the spleen can still be removed to control the bleeding but the problem is that hemangiosarcoma is an aggressive cancer. With the removal of the spleen and primary tumor, the patient is probably spared death by bleeding to death only to eventually succumb to cancer.
HOW DO WE DETECT SPLENIC MASSES?
There are several ways a dog can be determined to have a splenic mass. The first way, is by physical examination. A large firm mass in the area of the spleen may be palpable during a routine physical examination. From there, radiographs are taken of the belly to see if the mass appears to be on the spleen and radiographs of the chest are taken to see if there is evidence of cancer spread there. Based on these findings (plus basic blood work) a decision for or against spleen removal can be made. Unfortunately, many large dogs are simply too well muscled for splenic masses to be detected in this way.
Another method of detecting a splenic tumor comes on the basic blood panel. An unexplained “responsive anemia” is discovered. A responsive anemia is one typical of bleeding (as opposed to an anemia of chronic disease where red blood cells simply are inadequately produced.) An older large breed dog with an unexplained bleed is highly suggestive of a splenic tumor. The next step would be radiographs to see if a mass is apparent followed by chest radiographs for tumor spread as above. These findings on the blood panel are especially suggestive of a splenic mass if there has been a history of sudden weakness or collapse typical of a recent bleed. Splenic tumors tend to bleed chronically and slowly (and usually insignificantly) prior to a large bleed that produced obvious symptoms. These smaller bleeds are generally enough to alter the blood panel. If blood work is suggestive of a splenic mass, radiographs can be taken to confirm the presence of the mass.
It can be difficult to determine from the radiograph if the mass is coming from the liver or from the spleen.
IS IT BENIGN OR MALIGNANT?
This is not always clear prior to surgery. If there is evidence of tumor spread on a chest radiographs or ultrasound examination then one can be quite sure that the tumor is malignant. In this case it is likely too late to effect meaningful treatment though removing the spleen can at least prevent sudden bleeds.
If no evidence of tumor spread is present, the mass may be benign, or it may simply have produced tumor spread too small to see. In this case, one may simply proceed with splenectomy understanding that tumor spread may be obvious in the abdomen once the belly has been opened. Alternatively, one can have ultrasound performed on the belly to get a better idea of whether or not there is evidence of tumor spread.
If the spleen can be removed and minimal spread has occurred then chemotherapy is a reasonable treatment option for maximizing quality life span.
IF YOU CHOOSE NOT TO REMOVE THE SPLEEN
Unfortunately, eventually the dog will have a bleed from which he cannot recover. If you think your dog is having a bleed at home, you can apply an ace bandage around the belly in a snug manner to essentially apply pressure to the bleed. This is surprisingly effective and may stave off the inevitable.
Chemotherapy is not an option if the primary splenic tumor is left behind; however, since a large percentage of splenic tumors are benign and splenectomy is curative in this situation, we recommend reconsidering surgery.
OTHER REASONS TO REMOVE THE SPLEEN
We have already mentioned the splenic mass as well as excessive red blood cell removal by the spleen as reasons for splenectomy. There are some other situations where splenectomy may be needed:
When a dog with a splenic mass is going to have its spleen removed (“splenectomy”) there are some issues to understand.
THE MOST COMMON COMPLICATION OF SPLENECTOMY IS HEMORRHAGE (BLEEDING).
The spleen is supplied by numerous blood vessels which must be ligated or sealed in order for the spleen to be removed.
Page last updated: 1/11/2013