Cancer of the Lymphocytes in Dogs
Lymphoma is a type of cancer that originates in the lymphocyte cells of the immune system. A type of white blood cell, lymphocytes play an important and integral role in the body's defenses.
There are two forms of lymphocytes: B and T cells. Lymphoma may involve neoplastic proliferation of T or B, or non-B/non-T type lymphocytes, occurring primarily in the bone marrow, lymph nodes, and visceral organs. But mostly cases involving B-lymphocytes are seen in dogs.
Although rare in dogs, lymphoma is more prevalent in Boxers, golden retrievers, saint bernard, basset hounds, Airedale terriers, Scottish terriers, and bulldogs.
Symptoms and Types
Symptoms are variable depending upon the location and stage of tumor, but generally, the symptoms that are common in all forms of lymphoma are lack of appetite (anorexia), weakness, lethargy, and weight loss.
The exact cause is still unknown.
You will need to give your veterinarian a thorough history of your dog's health and onset of symptoms. The history and details you provide may give your veterinarian clues as to which organs are being primarily affected. Knowing the starting point can make diagnosis that much easier to pinpoint. Once the initial history has been taken, your veterinarian will perform a complete physical examination on your dog. Routine laboratory testing includes a complete blood count, biochemistry profile, and urinalysis.
The blood tests may reveal anemia, abnormally low levels of lymphocytes in the blood (lymphopenia), an abnormally high number of neutrophils (a type of white blood cell) in the blood (neutrophilia), an abnormally high number of monocyts (a type of white blood cell) in the blood, and abnormally low numbers of platelets (cells that are important in blood clotting), a condition called thrombocytopenia. The biochemistry profile may show abnormally high levels of liver enzymes and calcium, a common finding with lymphomas. Urinalysis results are usually found to be at normal levels in these patients.
More specific testing may be required for a confirmatory diagnosis. Diagnostic imaging, including X-rays and ultrasound, are often used to evaluate the size of regional lymph nodes. Your veterinarian will take bone marrow samples to be sent to a veterinary pathologist for further evaluation and to determine the extent of disease.