Even the healthiest dogs can develop cancer. In canines, intestinal cancer can come in several forms. Almost all of them, however, have the same symptoms. Unfortunately, the most prominent symptoms typically only appear when the disease has spread, making recovery less likely. Nevertheless, the earlier the disease is caught, the better the chances for survival.
According to the Dog Health Guide, gastric adenocarcinomas usually affect male dogs over 10 years old. The most common symptoms are vomiting (both normal, bloody, and projectile); reluctance or refusal to eat; sudden weight loss; and diarrhoea. Masses along the stomach, visible only to a veterinarian, are also a strong sign.
Gastrointestinal neoplasia, according to Pet Place, can occur in more places than just the intestines, even though the intestines are a common location of the cancer. It is most common in older dogs and in breeds such as collies and shepherds. It is characterised by malignant tumours. The tumour's severity is usually reflected in the symptoms, which can be severe or virtually nonexistent. The symptoms most commonly linked with tumours in the intestinal tract are black, messy stools; difficulty defecating; diarrhoea; loss of weight or appetite and vomiting.
Lymphosarcoma affects the lymph nodes, and since lymphoid tissue is found in the intestinal tract, lymphosarcoma can be a form of canine intestinal cancer. According to the Veterinary Hospital of the University of Pennsylvania, breeds most affected are pointers, shepherds, retrievers, boxers, and terriers. The most common symptom is inflamed lymph nodes. However, symptoms particular to intestinal lymphosarcomas are diarrhoea, vomiting, and loss of weight or appetite.