The most serious kind of blood tumor in dogs, hemangiosarcoma appears in the cell lining of the blood vessels. Most often, this type of tumor arises in the spleen, although it can also first appear in the liver or heart. From there, it quickly spreads to other organs. This blood tumor is virtually always fatal, although treatment can extend an animal's life. The sooner the disease is diagnosed, the longer your dog might live -- but that's easier said than done. Unfortunately, symptoms don't usually appear until the disease has already spread.
Sometimes, the first sign of hemangiosarcoma is finding a dead canine. Common symptoms include breathing problems, appetite and weight loss, exercise intolerance, weakness, seizures, heart arrhythmia, abdominal swelling, pale gums and collapse. Both abdominal swelling and breathing issues result from blood accumulation in the stomach or lungs, respectively.
While any dog can develop hemangiosarcoma, certain breeds appear predisposed. These include Bernese mountain dogs, border collies, Doberman pinschers, English setters, flat-coated retrievers, German shepherds, golden retrievers, Labrador retrievers, Portuguese water dogs and Skye terriers. Most affected dogs are middle-aged or older.
There is also a benign type of blood tumor known as hemangioma. Airedales, boxers, bull terriers, Gordon setters, greyhounds, Kerry Blue terriers, Scottish terriers and whippets are more likely to develop benign tumors. Even though benign, hemangiomas require surgical removal, since there is the potential for a growth to become malignant over time.
Diagnosis and Treatment
Hemangiosarcoma is a tough disease to diagnose, as a reliable, early test isn't currently available. Your vet will examine your dog and conduct blood and urine testing. She'll perform X-rays of your pet's chest, abdomen and other areas to detect where the tumor is located and where it has metastasized.
Once diagnosed, treatment includes tumor removal, along with the relevant organ. That's obviously not possible if the disease is in the heart, but splenectomy is common. Because this cancer involves the blood vessels, there's a greater risk of hemorrhage during the operation. Your vet will likely recommend chemotherapy post-surgery. Even with aggressive treatment, dogs diagnosed with hemangiosarcoma often don't live more than a few months.