Older Dogs With Lymphoma

Lymphoma is a cancer that affects mostly middle-age to older dogs. The majority of dogs that present with this disease--upward of 80 percent--do not have any signs of illness, but are brought for a check-up because of raised, hard lumps just under the surface of the skin.

  1. Definition

    • Lymphoma is predominately found in the lymph nodes, but also can be present in the spleen, liver and other organs, according to Drs. Foster and Smith of PetEducation.com. Many types of lymphoma exist, including leukemia, mycosis fungoides or cutaneous form (the kind that affects the skin), and mediastinal form (in the chest). It's important to remember that lymphoma can affect any area of the body that has lymph nodes.

    Causes

    • While there are no proven causes of cancer, there is some speculation. A correlation may exist between lymphoma and exposure to certain pesticides or magnetic fields, but more likely there is a genetic association with the disease. The Morris Animal Foundation notes that certain breeds are more susceptible to lymphoma than others, including boxers, cocker spaniels, golden retrievers and Labrador retrievers. Wendy C. Brooks, the educational director at VeterinaryPartner.com, urges owners of dogs with cancer not focus on the cause, but the treatment--and more importantly, the comfort and happiness of the dog.

    Symptoms

    • Firm lumps beneath the skin are usually the first signs of lymphoma. Other symptoms are often associated with the type or location of the disease. For instance, vomiting and diarrhea are associated with the gastrointestinal form of cancer; however, shortness of breath is evident in animals with lymphoma concentrated in the chest.

    Diagnosis

    • Blood and urine tests are the first step to diagnosing lymphoma. Confirmation of the diagnosis is made through a biopsy of one of the lymph nodes.

    Treatment

    • In untreated dogs, the prognosis is approximately four to six weeks, but treatment is available, not only to lessen discomfort and pain, but also to extend the lifespan of the patient. Current treatments include chemotherapy, injectable drugs, or a combination of both, according to Foster and Smith. Brooks claims a 75 percent remission rate for dogs that are given some type of treatment, but expense and length of remission must be taken into account.