Canine Lymphoma
A Deadly Dog Disease

"Owners are often shocked when a diagnosis of lymphoma is made because many pets
do not seem to feel sick in the early stages of the disease."

Many different types of cancers can affect dogs. Canine lymphoma, which also goes by the names "lymphosarcoma" or "LSA," is extremely common and eventually fatal in most cases. However, with treatment many dogs can enjoy an excellent quality of life for many months or even years.

Overview/Snapshot of the Disease

Lymphoma is a cancer of an immature form of lymphocyte, a type of white blood cell, called a lymphoblast. During the course of this disease, lymphoblasts replicate themselves in an uncontrolled manner and can invade many different tissues including lymph nodes, liver, spleen, skin, digestive tract, kidneys, and bone marrow. Most dogs develop "multicentric lymphoma" during which lymph nodes, and sometimes the liver, spleen, and bone marrow are involved.

Lymphoma is most commonly diagnosed in middle-aged to older dogs. Some breeds have a higher incidence of the disease including Golden Retrievers, German Shepherds, Rottweilers, Basset Hounds, and Scottish Terriers, but any dog, including mutts, can develop lymphoma.

Canine Lymphoma Symptoms

The symptoms of this dog disease are related to the location of tumors.

• When external lymph nodes are involved, owners might notice abnormally large lumps under the jaw, in front of the shoulder blades, or behind the knees.
• Lymphoma of the skin can cause patches of hair loss, flakiness, redness, ulcers, itchiness, and/or the development of skin masses.
• When lymph tissues in the chest are involved dogs may have difficulty breathing.
• The gastrointestinal form of the disease can cause vomiting, diarrhea, loss of appetite, and weight loss.

Owners are often shocked when a diagnosis of lymphoma is made because many pets do not seem to feel sick in the early stages of the disease. Other dogs, however, do develop general signs of illness like fever, lethargy, and a loss of appetite.

Causes of Canine Lymphoma

We do not know why dogs develop lymphosarcoma. Genetics may play a role in some cases, but for most patients no underlying cause can be determined.

Treatment of Canine Lymphoma

Treatment can only begin after a definitive diagnosis of lymphoma has been reached. Your veterinarian may need the results of blood work, a urinalysis, fine-needle aspirates, biopsies, x-rays, ultrasounds, and other tests to rule out other causes of your dog’s symptoms and recommend appropriate forms of therapy.

Without treatment, dogs with lymphoma generally only live for a month or two after diagnosis. Surgery or radiation is an option if your dog's cancer primarily involves a single part of his body, but chemotherapy is by far the most common method of dealing with lymphoma in dogs.

Many different protocols are available. Some are relatively simple and inexpensive but also generally bring about shorter remissions. More complicated protocols can produce remissions that last for a year or longer, but they do involve frequent trips to the veterinarian and greater expense. Usually, dogs do not feel sick while undergoing chemotherapy.

Prevention of Lymphoma in Dogs

Because we do not know what causes canine lymphoma, we also do not know how to prevent it at this time. If your dog develops any of the symptoms of this disease, take him to the veterinarian immediately so that an accurate diagnosis can be reached and appropriate treatment started in a timely manner.

Consulting Veterinarian: Jennifer Coates, DVM

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