Lymphoma, also known as Lymphosarcoma, is one of the most common types of cancers to effect dogs. Dogs of any breed or age are susceptible to lymphoma but, there are certain breeds that are more genetically predisposed to an increased risk of developing lymphoma. Scottish Terriers, German Shepherds, St. Bernards, Boxers, Poodles, Rottweilers, and Golden Retrievers are breeds that are much more likely to be effected. In fact, one in every eight Golden Retrievers will get lymphoma. Even more disturbing, 60% of Golden Retrievers will die of some form of cancer.
Lymphocytes are a type of white blood cell thats helps make up the immune system of vertebrate animals. Lymphoma is the reproduction of cancerous lymphocytes within various organs such as bone, stomach, intestines, and lymph nodes, therefore, this proliferation of malignant cells can lead to many different forms of lymphoma.
There are many types of lymphoma that can effect many different parts of the dog. Extranodal lymphoma, the most rare type of lymphoma, can effect eye, liver, skin, bone, mouth, and breast tissue. Mediastinal lymphoma can effect the thorax and lungs. Gastrointestinal lymphoma is cancer in the stomach and intestines. The most common type of lymphoma, making up 85% of all cases of lymphoma, is multicentric lymphoma which effects the lymph nodes.
For the most part, symptoms of lymphoma are generic and can mimic the symptoms of other diseases or illnesses. Some of these symptoms include, but are not limited to: depression, lethargy, weight loss, fever, cough, labored breathing, difficulty swallowing, diarrhea, vomiting, disorientation, changes in behavior, melena, increased thirst, and increased urination.
Signs and symptoms of lymphoma will differ depending on the area effected by the condition. Mediastinal lymphoma, for example, is lymphoma in the mediastinum located in the middle of the chest cavity so, a dog with that condition may see symptoms of labored breathing, fluid around the lungs, and other symptoms that resemble congestive heart failure.
Gastrointestinal lymphoma can be present anywhere along the digestive tract, from stomach to rectum. Symptoms include vomiting, diarrhea, lethargy, weight loss, loss of appetite, and melena, or tarry black feces indicating a gastrointestinal hemorrhage.
Multicentric lymphoma is the most common type of lymphoma in canines. Multicentric lymphoma is an enlargement of the lymph nodes in the neck, behind the knees, in the groin, or in other lymph nodes located in the body such as lymph nodes located near the spleen and liver. The malignant growth isn’t necessarily painful in the beginning stages.
If a person suspects that their dog has enlarged lymph nodes, after confirmation by a veterinarian, a urinalysis and blood tests would be conducted. Also, to confirm a diagnosis of lymphoma, a biopsy is taken of the enlarged lymph node(s).
While radiation therapy and surgery are used to treat canine lymphoma, chemotherapy is the most common and most recommended form of treatment. Since lymphoma is highly variable in it’s severity and how it effects an animals health, effectiveness of treatment is also highly variable. Treatment of lymphoma is largely palliative, since a cure for lymphoma is extremely rare. However with a combination of chemotherapy drugs, a remission of 6 – 8 months is achievable, with a total survival time of about 9 – 12 months.
If left untreated, a dog diagnosed with canine lymphoma has a prognosis of about 60 days.
Lymphoma is a progressive cancer which is fatal in most every case. Identifying the cancer in its early stages is key to helping a dog have a longer and pain free life. If your dog is experiencing symptoms that I mentioned above, consult your veterinarian.