November is Pet Cancer Awareness Month. Among the most deadly of canine cancers is hemangiosarcoma, or cancer of the blood vessels. Hemangiosarcoma can either present as skin cancer, which can be successfully treated if caught early enough, or as cancer of the internal organs, particularly the spleen or the heart. The prognosis for splenic or cardiac hemangiosarcoma is extremely poor, even with aggressive treatment, as frequently the first sign of any problem is when the tumor ruptures and causes massive internal bleeding. An additional complication arises from the fact that since it is a blood vessel cancer, the cancer cells have usually spread to other areas of the body by the time of diagnosis. As a result, the median survival time for internal tumors post-diagnosis is measured in weeks or months, even with surgery and chemotherapy. Hemangiosarcoma can occur in any breed, but there is an identified pre-disposition in German Shepherd dogs, labrador retrievers and golden retrievers. Within my own circle of pet parent friends, in the past year we have lost a Siberian husky, an Australian shepherd, a golden retriever and my own miniature poodle, Tiny, to hemangiosarcoma.
What are the signs and symptoms to watch for? For skin-based tumors, any unusual growth on the skin should be evaluated by your veterinarian and biopsied if there is any suspicion of cancer. It is a good idea to check your pet’s skin frequently, particularly as he ages, for any abnormal lumps or bumps. Many are benign, but only your veterinarian and a pathologist can identify cancerous skin growths.
For internal organ cancer, the signs can be much more subtle, and sometimes non-existent. In the cardiac form of hemangiosarcoma, you might notice weakness, weight loss, loss of appetite, difficulty breathing or difficulty recovering from any kind of exertion. These can all be signs of simple aging, other heart or lung problems, or tumor growth. Again, a visit to your veterinarian is in order for possible x-rays, ultrasound, CT or other diagnostic scans to determine the cause of the problem. If not diagnosed, the heart tumor will eventually rupture and cause massive internal hemorrhage.
In the splenic form of hemangiosarcoma, unless the tumor is extremely large and can be felt on abdominal exam, the first warning sign might be total collapse when the tumor ruptures. In Tiny’s case, he exhibited greater than usual “old man weakness” one evening at home, and could not stand up. He was seventeen years old at the time, and had a bulging abdomen to begin with due to loss of muscle tone associated with aging. I quickly rushed him to the veterinary emergency clinic (he was never one to have his emergency situations during regular veterinary clinic hours), where the doctor quickly tapped his abdomen and withdrew bloody fluid. She talked with me about her suspicions that a splenic tumor had ruptured, and recommended an ultrasound to confirm her diagnosis. Ultrasound did show a very large spleen as well as some suspicious spots on the liver. We discussed the two options: surgery to remove the spleen and the suspect portions of his liver or euthanasia. Given his age and all of the potential complications, we made the difficult decision to say goodbye.
But, when they brought Tiny into the room for that final procedure, he had miraculously recovered from his collapse, was very excited to see us, and started asking us to play with him. The veterinarian suspected that the internal bleeding had stopped and that he had re-transfused himself. After more discussion of the other alternatives and based on the fact that he seemed to be telling us that he wasn’t ready to go just yet, we brought him home and scheduled a specialist visit early the next morning.
Tiny had a splenectomy and partial liver lobectomy, and came through the surgery with flying colors, especially given his age. We opted for a shortened and low-dose course of chemotherapy, and for the remainder of his life he took several mild medications such as doxycycline and Deramaxx to help keep the cancer at bay. He also received acupuncture and Chinese herbal formulations in addition to Western medicine. In spite of the six months or less that most hemangiosarcoma patients survive, Tiny lived another two and a half years until the cancer spread to his brain and his mouth. When he began to have difficulty eating and started having seizures, it was time to help him cross the “Rainbow Bridge.” His outcome and length of survival with good quality of life was unusually positive, but he was a fighter with a strong will to live.
Survival in hemangiosarcoma is largely a function of how early it is caught and whether it is a surface/skin lesion instead of an internal tumor. Treatment options may be limited, especially if a tumor ruptures, and diagnostics, surgery and chemotherapy can be expensive. You know your dog better than anyone else, and are in the best position to make informed decisions (with the help of your veterinarian) as to the best course of action if this deadly cancer strikes your dog.