Causes of Hemangiosarcoma
The actual causes of hemangiosarcoma, like the causes of most other types of cancer, are not well understood. Hemangiosarcomas can develop anywhere on the surface of a dog’s body, inside its internal organs or within body cavities. Primary hemangiosarcomas tend to occur most frequently in the skin, heart, spleen, liver and bone. Wherever they start, hemangiosarcomas initially are formed from cells lining small blood vessels. They are predisposed to spreading rapidly to remote areas of the dog’s body. This is referred to as “metastasis,” or “seeding of the cancer.”
Hemangiosarcoma of the heart is one of the most common cardiac cancers in companion dogs. The causes of hemangiosarcoma that develops inside a dog’s body, such as in or around the spleen, liver, heart and bones, remain a medical mystery. However, the fact that certain breeds and sizes of dogs are predisposed to developing hemangiosarcoma strongly suggests that there is a genetic component to its cause. Hairless areas of a dog’s skin, like the belly and inner thighs, are prone to developing dermal, or cutaneous, hemangiosarcomas. The terms “dermal” and “cutaneous” refer to the skin. Dogs with this type of hemangiosarcoma often have a history of prolonged exposure to sunlight. Dermal hemangiosarcoma usually shows up as a solitary tumor and is not as likely to spread – or to metastasize – as other types of this cancer. Hemangiosarcoma can also occur in the subcutaneous areas just under the skin; this form of the disease is not thought to be associated with ultraviolet light exposure.
Prevention of Hemangiosarcoma
To reduce the risk of hemangiosarcoma of the skin, lightly colored dogs, short-haired dogs and dogs with especially thin haircoats should not be left out in the sun for long periods of time without being provided with some source of shelter. There is no known way to prevent internal hemangiosarcoma from forming and spreading. Certainly, feeding a high-quality diet and having fresh water freely available can help to promote a long, healthy, and hopefully disease-free life. It is also a good idea to have companion dogs seen by a veterinarian regularly for check-ups and vaccination boosters. Routine blood work, a urinalysis and a thorough physical examination, done annually, can identify diseases or disorders of the kidneys, liver, spleen, adrenal glands, heart, lungs, thyroid gland and other vital organs, even before the dog’s owner sees any symptoms of illness.
Early identification of medical problems is one of the best ways to prevent or delay progression of the condition and improve the dog’s chances of partial or complete recovery. However, until the actual causes of hemangiosarcoma are better understood, this invasive and often deadly type of cancer will to continue to haunt owners of companion dogs.