Signs and symptoms of a bleeding tumor in the abdomen of a dog are generally gastrointestinal in nature, but depend on the type of cancer involved. By the time a dog develops symptoms, it's likely the disease is fairly advanced. While some symptoms appear gradually, others are sudden and often fatal. While the prognosis isn't good for these types of canine cancers, proper treatment can give your dog a good quality of life in his remaining time.
Canine Gastrointestinal Cancer
Gastrointestinal cancer is fairly uncommon in dogs, but it does occur. The most common type of canine cancer affecting the intestinal tract is lymphoma, followed by adenocarcinoma. Dogs over the age of 9 are most likely to develop the disease, with males affected more than females. German shepherds and collies appear predisposed to gastrointestinal cancer.
Dogs suffering from gastrointestinal cancer might experience vomiting, diarrhea, appetite loss and weight loss. Blood in the feces, or tarry, dark stools, could indicate the tumor is bleeding. Small amounts of blood might appear in the vomit. If the tumor is large enough to cause a blockage, your dog becomes severely constipated and in obvious pain. All of these symptoms resemble other gastrointestinal diseases and conditions, so your veterinarian must perform X-rays, ultrasounds and blood tests to determine the cause.
While lymphoma most often develops in the lymph system, it can appear anywhere in the body. Besides gastrointestinal symptoms, dogs with intestinal lymphoma might develop jaundice, or a yellowing of the gums, skin and whites of the eyes, if the cancer is based in the liver. Coughing and other respiratory issues are also lymphoma symptoms. Lymphoma generally isn't treated surgically. Treatment usually consists of chemotherapy. Depending on the stage of the disease, dogs with chemotherapy can live for a year or more after treatment.
Your dog's spleen sits near the abdomen. Cancer of the spleen usually results from hemangiosarcoma, or cancer of the blood vessels. While this cancer can grow in other organs, the spleen is the most common site. Often, there is no sign of illness until the tumor ruptures, dumping blood into the abdomen. At that point, the dog might go into shock, collapse and die. If the tumor hasn't ruptured, the dog's abdomen might appear distended and he appears lethargic. Treatment involves removing the spleen, but even with treatment affected dogs rarely live more than a few months.