German Shepherd Hemangiosarcoma (HSA) | Canine Hemangiosarcoma | Malignant Hemangiothelioma | Angiosarcoma | Blood Vessel Cancer
German Shepherds are prone to Hemangiosarcoma, also known as HSA, malignant Hemangiothelioma, angiosarcoma, or blood vessel cancer, which is a cancer that originates in the vascular endothelial cells that line the capillaries; however, despite their place of origin, these cancers metastasize swiftly and aggressively, often afflicting the spleen (a significant percentage of spleen cancers are in fact the result of hemangiosarcoma). This kind of cancer is more common in the German Shepherd dog than in any other breed, although Labrador Retrievers, Boxers, Pointers, and Poodles are also affected. While dogs of all ages are at risk for this condition, it appears that older dogs are at higher risk for this condition, with the mean age of affliction occurring between 8 and 13 years of age.
While the precise cause of the cancer is uncertain, it appears that ultraviolet light exposure plays some role in development: often hemangiosarcoma arises in areas of the dog where hair (and hence, protection) is sparse. Noncutaneous forms of the cancer tend to metastasize faster (upwards of 80% of cases have already metastasized at diagnosis), while cutaneous forms of the cancer can metastasize more slowly. It is important to be extra vigilant in looking for signs of hemangiosarcoma in German Shepherd dogs, given their high risk rate for this particular form of cancer. The symptoms can be varied, as in some cases only sudden death will make plain that anything at all is wrong, and earlier symptoms will be limited at best. Often this occurs when a cancer ruptures some part of the body, causing internal hemorrhaging. Yet often less obvious signs are present, which includes muscle weakness, distention in the abdominal area, weight loss, mucous membrane pallor, and a history of weakness or collapse possibly caused by internal bleeding.
When hemangiosarcoma is present in the cardiac area, arrhythmias and other cardiac problems will occur. However, a full diagnosis can only be made with a complete blood count, abdominocentesis, serum chemistry profile, and/or radiographs and EKGs. These tests will confirm not only the presence or absence of the disease, but also its progression, which can better determine what course of treatment, if any, is best. If the cancer has not metastasized already, the preferred course of treatment for this form of cancer is surgical: removing a bleeding mass of hemangiosarcoma from your German Shepherd dog will slow down the progression of the disease and its clinical signs, although it may not cure the cancer altogether. Unfortunately, the fast rate of metastasis with this cancer means that this is not a common option. Splenic HSA can be addressed with a splenectomy, and cardiac HSA can merit a surgical resectioning of the right auricular mass in some instances.
Cutaneous and some forms of subcutaneous hemangiosarcoma can also be addressed surgically, particularly as it is less likely to have spread. However, in most cases, instances of this cancer deeper than the skin or subcutaneous layer are not treatable surgically, and chemotherapy is necessary (often using doxorubicin). Immunomodulator therapy is an additional form of therapy that may, when combined with traditional chemotherapy, lengthen survival times.
Without chemotherapeutic treatment, the one-year survival rate is less than 10% of afflicted dogs; however, chemotherapy can increase the average length of survival to six months after diagnosis. In addition, dogs suffering from the less serious form, cutaneous hemangiosarcoma, have been shown to live up to two years on average with treatment.