Gastrointestinal Neoplasia in Dogs

This type of cancer typically occurs in canines as opposed to felines, with adenocarcinomas being the most common type. Dogs are typically 6 to 9 years old at onset. You must take your pet to the veterinarian if you notice symptoms like lethargy, vomiting, diarrhea, difficulty with eating, or bleeding coming from the mouth. You should also be proactive any time there are symptoms such as loss of weight and regurgitation. Do not hesitate to take your pet to the veterinarian in order to rule out illnesses that may present in a similar way to cancer. The treatment may be long term, with the prognosis depending on the extent of the condition.

Gastrointestinal neoplasia is a cancerous disease, primarily of the GI tract. This includes the duodenum, colon, and rectum.

The symptoms for gastrointestinal neoplasia in dogs consist of several variations. Not all dogs have the same symptoms, but there are some clinical signs that are inevitable. You can expect symptoms which may include:

• Dehydration
• Lack of saliva in the mouth
• Poor digestion
• Constipation
• Diarrhea
• Body language exhibiting depression
• Abnormal bowel movements
• Vocalization
• Scratching or licking the body
• Anorexia
• Vomiting that includes blood
• Abdominal distension due to fluid

Types

• Adenocarcinoma
• Lymphoma
• Gastrointestinal stromal tumor
• Carcinoid
• Mast cell tumor
• Leiomyosarcoma

• Age may be a factor in many types of gastrointestinal neoplasia
• The average age is six to nine years
• Breed predisposition has been noted in studies (German Shepherd, Belgian Shepherd, Collie)
• Males may be predisposed
• Adenocarcinomas are common and often metastasize (as many as 95% in one study)
• The masses are often in the stomach, rectum or colon
• Lymphoma often affects the small intestine and liver
• Leiomyosarcomas are typically found in the small intestine

Your veterinarian will conduct gastric radiographs to verify if there is ulceration in the gastrointestinal tract. Lesions and tumors may be indicated with the use of contrast. An ultrasound could reveal a thickening of your dog’s GI tract and blood tests may show hypoglycemia, hypokalemia, and electrolyte changes.

A fine needle aspirate or needle biopsy may be suggested though the biopsy may be difficult for tumors that are submucosal. Additional imaging could include thoracic x-rays. Exploratory surgery is often considered; the advantage of this is that in some cases, a tumor may be removed during the investigation.

In some cases, the lesions may be difficult to reach and therefore, complete excision is a challenge. The treatment will be decided based on the best case scenario for your companion. 

Hospitalization for removal of a tumor will involve preoperative testing and preparation. Low risk tumor removal can offer a promising prognosis. In the case of a tumor considered high risk, or if the cancer has metastasized, the recovery outlook is more guarded. Chemotherapy will be indicated in this case.

As well, in the case of lymphoma for example, chemotherapy will be the chosen treatment. Additionally, nutritional management and non-steroidal anti-inflammatory drugs will be prescribed as a means to deal with the diagnosis.

Canines who receive a complete excision surgery have a fair to good prognosis, though it should be noted that the survival time is often under an additional three years, depending on the type of gastrointestinal cancer. In dogs where the cancer has metastasized, the prognosis may mean loss of life within 3 months of diagnosis. However, consultation with your veterinarian will involve discussion of your pet’s general health status and the benefits as opposed to life quality for your dog.

Medication should be administered as instructed by the veterinarian. Follow up visits are essential as they will involve the administration of the chemotherapy treatments. Do exactly as your veterinarian instructs. If there are recurring signs, be sure to contact your veterinary specialist right away. Often, cancer of this type is in the advanced stages when it is diagnosed. Your veterinarian will make a professional prognosis as is determined by your dog’s particular case.