Sarcomas are malignant tumors that arise from various sources, including
connective tissue, fat, blood vessels, nerve sheaths, and muscle cells.
Collectively they account for about 15 percent of all cancers in dogs. There is a genetic disposition among
German Shepherd Dogs, Boxers, Saint Bernards, Basset Hounds, Great Danes, and
Sarcomas occur on the surface of the body and within organs. They tend to
grow slowly and metastasize only when they have been present for some time.
Metastases usually involve the lungs and liver. Some sarcomas are well defined
and appear to be encapsulated; others infiltrate the surrounding tissue and
have no distinct margins. Sarcomas within body cavities often grow to a large
size before being discovered.
Submissive urination is normal canine communication. Dogs do it to show social appeasement. When a dog submissively urinates, he’s trying to convey that he’s not a threat. Not all dogs submissively urinate. However, some will urinate when they’re exceptionally excited or feeling submissive or intimidated. Dogs who submissively urinate usually do so when greeting people or animals (especially unfamiliar ones), during exciting events, while playing, during physical contact, such as petting, or...
Hemangiopericytoma, arising from cells surrounding small arteries
Fibrosarcoma, arising from fibrous connective tissue
Hemangiosarcoma, arising from cells that make up the lining of small blood
Schwannoma, a tumor of nerve sheaths
Osteosarcoma, a tumor of bones
arising in lymph nodes and in organs that contain lymphoid tissue, such as the
spleen, liver, and bone marrow
Treatment: The World Health Organization has established a staging system
for canine soft tissue sarcomas similar to that described for mast cell tumors.
Depending on the type of sarcoma and the extent of local involvement, treatment
may involve surgical excision with a margin of normal tissue, radiation
and chemotherapy. A specific treatment plan often uses a combination of
therapies. The prognosis depends on the stage of the tumor at the time of
Lymphoma, also called lymphosarcoma, is a type of cancer that arises (often
simultaneously) in lymph nodes and in organs that contain lymphoid tissue such
as the spleen, liver, and bone marrow. The disease affects middle-aged and
older dogs. It should be suspected when enlarged lymph nodes are found in the
groin, armpit, neck, or chest. Affected dogs appear lethargic, eat poorly, and
lose weight. The liver and spleen are often enlarged.
Chest involvement results in pleural effusion and severe shortness of
breath. Skin involvement produces itchy patches or nodules on
the surface of the skin that mimic other skin diseases. Intestinal involvement
A complete blood
count may show anemia
and immature white blood cells. The serum calcium is elevated
in 20 percent of dogs with lymphoma. Blood and liver function tests are usually
abnormal. A bone marrow biopsy is helpful in determining if the disease is
Chest and abdominal X-rays and ultrasonography are particularly valuable in
identifying enlarged lymph nodes, organs, and masses. A diagnosis can also be
made by fine needle aspiration of an enlarged lymph node. In questionable
cases, the entire lymph node should be removed for more complete