Literally cancer can form anywhere in the body, and hemangiosarcomas are cancerous cells and tumors that form in the blood vessels throughout a dog's body. Any breed of dog can develop hemangiosarcomas although they are most common in breeds such as the German Shepherd, Boxer, English Setter and Golden Retriever. Since it is most common in these particular breeds of dogs there is likely a genetic factor that contributes to the development of the cancer, although the exact link or marker is not known. It is interesting to note that hemangiosarcomas are very rare in other species of pets with cats rarely if ever developing the condition. Humans also very rarely develop hemangiosarcomas, which means that research on this cancer is really specific to researchers working with canine cancers.
Usually hemangiosarcomas develop where there are rich networks of blood vessels. The most common locations for the tumors include the spleen, liver, heart and in the skin, however this cancer can occur almost anywhere in the body. Hemangiosarcomas found on the skin are the most treatable of the group as the skin can be removed through surgical procedures whereas removing the internal organs or even parts of the internal organs is usually not an option. The first signs of hemangiosarcomas that owners typically notice are large, solid masses in the abdominal area if the hemangiosarcomas is in the liver or spleen. For hemangiosarcomas in the heart typically lack of energy, inability to exercise, poor condition, lack of appetite and coughing and wheezing are often noted, but they may be confused with any number of other health conditions including what owners may see as part of the natural aging process of the dog. When tumors rupture or bleed internally there may be signs such as pale gums, dizziness, collapse, irregular heartbeat and general weakness of the legs.
Diagnosis is typically confirmed by chest x-rays in the case of tumors in the heart or abdominal x-rays or ultrasound test. After the tumor is confirmed most of the time vets will also test the other organs to check if the hemangiosarcomas has metastasized through the body. A biopsy will also be performed to confirm that the tumor is malignant. Since this is a very aggressive form of cancer it is common that the cancer will have already spread to other organs by the time it is diagnosed. Often the full extent of the spread of the cancer is not fully known until the surgery is performed.
For the internal types of hemangiosarcomas the options include surgical removal of the tumors and chemotherapy to treat the cancerous cells. Unfortunately even with both surgery and chemotherapy only about 10% of all treated dogs survive one year after the diagnosis. If the hemangiosarcomas is discovered early in the development of the cancer and it has not metastasized to other organs, the treatment success rate can be higher. Typically treatment options will be considered in regards to improving the dog's quality of life and managing any diseases or conditions that may occur along with the hemangiosarcomas that may weaken or compromise the dog's health.