Spleen cancer in dogs can be either benign or malignant. The spleen is a flat, rectangular organ that removes pathogens and dead blood cells from the bloodstream. T
his spongy organ is located behind the stomach and just under the diaphragm. The spleen can develop masses around it and these can be either benign or malignant.
Hemangiosarcomas are a common type of spleen cancer in dogs and occur generally in the spleen or the heart. It is also the most common cause of abdominal hemorrhages.
As both hemangiomas and hemangiosarcomas develop from the blood vessels of the red pulp, it results in the propagation of uncharacteristic blood vessels.
Finally, these abnormal blood vessels burst and the spleen bleeds profusely. The bleeding may stop within a day, but sooner or later the mass will bleed again.
Excessive bleeding results in extreme weakness and sensitivity to cold. It also changes the color of the gums to a pale shade. If the dog has not lost too much blood and the tumor is benign, surgery normally resolves the condition.
Even so, it is more beneficial to remove the spleen as soon as the tumor is discovered instead of waiting for the bleeding to happen. If the spleen is actively bleeding, the dog may have to be moved immediately to an emergency facility to have it removed.
Hemangiosarcomas, being malignant, need to be managed differently. Hemangiosarcomas cause anemia, low platelets and coagulations in the vascular system and an abnormal rate of muscular contractions.
Malignant spleen tumors also need to be removed surgically. However, spleen tumors in dogs are highly metastatic and there is a great likelihood that the cancer would have spread widely throughout the dog's body.
Almost 66% of spleen cancer in dogs are malignant and two thirds are hemangiosarcomas. Malignant cancer of any type is a potentially fatal condition. Hemangiosarcoma, however, is slightly different from other types of cancers in dogs.
It is a blood-fed sarcoma, which means that the abnormal blood vessels develop within the tumor and are basically filled with blood. The most common cause of death is rupturing of the tumor which causes the dog to bleed to death.