Mediastinal Cancer in a Dog

Mediastinal is a rare canine lymphoma. It is characterized by malignant tumors that grow in the lymph tissue and spread. Mediastinal develops in the center of the chest and is associated with the lungs and thymus gland. Lymphoma can occur in any breed but it is most common in the golden retriever, basset hound, German shepherd, Scottish and Airedale terrier, bulldog, poodle and Saint Bernard. In addition to a genetic predisposition, chemicals in the environment such as household cleaning products, solvents and smoke and a suppressed immune system may lead to higher risk.

  1. Types

    • There are four general types of canine lymphoma: multicentric, gastrointestinal, mediastinal and extranodal. Multicentric is the most common. Lymphomas are diagnosed in five stages. Stage 1 is the least serious and generally involves a single lymph node. Stage 5 is the most critical, involving the bone marrow, blood and other organs. Dogs with untreated mediastinal cancer have an average life expectancy of four to six weeks. Cancer treated with chemotherapy prolongs the dog's life approximately one year.

    Symptoms

    • The most common symptoms associated with mediastinal lymphoma are fatigue and labored breathing. Tumors restrict the function of the lungs. causing fluid to build up and leading to suffocation. The disease mimics the same signs as congestive heart failure. This disease can strike any dog at any age but is most common in middle-aged and older dogs. Other symptoms include raised lesions on the skin or pale plaques, weight loss, loss of appetite and fever.

    Diagnosis

    • Testing varies based on the symptoms and location. Blood work is performed to check for abnormalities such as calcium. Calcium levels will be high with mediastinal cancer. Other testing may include X-rays, ultrasound and urinalysis. If a tumor is found it may be aspirated or biopsied to determine the type and stage of cancer present.

    Treatment

    • Surgery is rarely an option with this type of cancer because it is a systemic disease. Chemotherapy is used most often. Where chemotherapy is not an option, a combination of oral and injected drugs may be given weekly to prolong life and decrease symptoms. In addition to medical care, a nutritional plan that includes a low carbohydrate diet, which is rich in omega-3, may be required to support the immune system.